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@y86-dev y86-dev commented Sep 16, 2023

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y86-dev pushed a commit that referenced this pull request Oct 9, 2023
The following call trace was observed:

localhost kernel: nvme nvme0: NVME-FC{0}: controller connect complete
localhost kernel: BUG: using smp_processor_id() in preemptible [00000000] code: kworker/u129:4/75092
localhost kernel: nvme nvme0: NVME-FC{0}: new ctrl: NQN "nqn.1992-08.com.netapp:sn.b42d198afb4d11ecad6d00a098d6abfa:subsystem.PR_Channel2022_RH84_subsystem_291"
localhost kernel: caller is qla_nvme_post_cmd+0x216/0x1380 [qla2xxx]
localhost kernel: CPU: 6 PID: 75092 Comm: kworker/u129:4 Kdump: loaded Tainted: G    B   W  OE    --------- ---  5.14.0-70.22.1.el9_0.x86_64+debug #1
localhost kernel: Hardware name: HPE ProLiant XL420 Gen10/ProLiant XL420 Gen10, BIOS U39 01/13/2022
localhost kernel: Workqueue: nvme-wq nvme_async_event_work [nvme_core]
localhost kernel: Call Trace:
localhost kernel: dump_stack_lvl+0x57/0x7d
localhost kernel: check_preemption_disabled+0xc8/0xd0
localhost kernel: qla_nvme_post_cmd+0x216/0x1380 [qla2xxx]

Use raw_smp_processor_id() instead of smp_processor_id().

Also use queue_work() across the driver instead of queue_work_on() thus
avoiding usage of smp_processor_id() when CONFIG_DEBUG_PREEMPT is enabled.

Cc: [email protected]
Suggested-by: John Garry <[email protected]>
Signed-off-by: Nilesh Javali <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Martin K. Petersen <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
Inject fault while probing kunit-example-test.ko, if kstrdup()
fails in mod_sysfs_setup() in load_module(), the mod->state will
switch from MODULE_STATE_COMING to MODULE_STATE_GOING instead of
from MODULE_STATE_LIVE to MODULE_STATE_GOING, so only
kunit_module_exit() will be called without kunit_module_init(), and
the mod->kunit_suites is no set correctly and the free in
kunit_free_suite_set() will cause below wild-memory-access bug.

The mod->state state machine when load_module() succeeds:

MODULE_STATE_UNFORMED ---> MODULE_STATE_COMING ---> MODULE_STATE_LIVE
	 ^						|
	 |						| delete_module
	 +---------------- MODULE_STATE_GOING <---------+

The mod->state state machine when load_module() fails at
mod_sysfs_setup():

MODULE_STATE_UNFORMED ---> MODULE_STATE_COMING ---> MODULE_STATE_GOING
	^						|
	|						|
	+-----------------------------------------------+

Call kunit_module_init() at MODULE_STATE_COMING state to fix the issue
because MODULE_STATE_LIVE is transformed from it.

 Unable to handle kernel paging request at virtual address ffffff341e942a88
 KASAN: maybe wild-memory-access in range [0x0003f9a0f4a15440-0x0003f9a0f4a15447]
 Mem abort info:
   ESR = 0x0000000096000004
   EC = 0x25: DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
   FSC = 0x04: level 0 translation fault
 Data abort info:
   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
 swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000000441ea000
 [ffffff341e942a88] pgd=0000000000000000, p4d=0000000000000000
 Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
 Modules linked in: kunit_example_test(-) cfg80211 rfkill 8021q garp mrp stp llc ipv6 [last unloaded: kunit_example_test]
 CPU: 3 PID: 2035 Comm: modprobe Tainted: G        W        N 6.5.0-next-20230828+ Rust-for-Linux#136
 Hardware name: linux,dummy-virt (DT)
 pstate: a0000005 (NzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : kfree+0x2c/0x70
 lr : kunit_free_suite_set+0xcc/0x13c
 sp : ffff8000829b75b0
 x29: ffff8000829b75b0 x28: ffff8000829b7b90 x27: 0000000000000000
 x26: dfff800000000000 x25: ffffcd07c82a7280 x24: ffffcd07a50ab300
 x23: ffffcd07a50ab2e8 x22: 1ffff00010536ec0 x21: dfff800000000000
 x20: ffffcd07a50ab2f0 x19: ffffcd07a50ab2f0 x18: 0000000000000000
 x17: 0000000000000000 x16: 0000000000000000 x15: ffffcd07c24b6764
 x14: ffffcd07c24b63c0 x13: ffffcd07c4cebb94 x12: ffff700010536ec7
 x11: 1ffff00010536ec6 x10: ffff700010536ec6 x9 : dfff800000000000
 x8 : 00008fffefac913a x7 : 0000000041b58ab3 x6 : 0000000000000000
 x5 : 1ffff00010536ec5 x4 : ffff8000829b7628 x3 : dfff800000000000
 x2 : ffffff341e942a80 x1 : ffffcd07a50aa000 x0 : fffffc0000000000
 Call trace:
  kfree+0x2c/0x70
  kunit_free_suite_set+0xcc/0x13c
  kunit_module_notify+0xd8/0x360
  blocking_notifier_call_chain+0xc4/0x128
  load_module+0x382c/0x44a4
  init_module_from_file+0xd4/0x128
  idempotent_init_module+0x2c8/0x524
  __arm64_sys_finit_module+0xac/0x100
  invoke_syscall+0x6c/0x258
  el0_svc_common.constprop.0+0x160/0x22c
  do_el0_svc+0x44/0x5c
  el0_svc+0x38/0x78
  el0t_64_sync_handler+0x13c/0x158
  el0t_64_sync+0x190/0x194
 Code: aa0003e1 b25657e0 d34cfc42 8b021802 (f9400440)
 ---[ end trace 0000000000000000 ]---
 Kernel panic - not syncing: Oops: Fatal exception
 SMP: stopping secondary CPUs
 Kernel Offset: 0x4d0742200000 from 0xffff800080000000
 PHYS_OFFSET: 0xffffee43c0000000
 CPU features: 0x88000203,3c020000,1000421b
 Memory Limit: none
 Rebooting in 1 seconds..

Fixes: 3d6e446 ("kunit: unify module and builtin suite definitions")
Signed-off-by: Jinjie Ruan <[email protected]>
Reviewed-by: Rae Moar <[email protected]>
Reviewed-by: David Gow <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
Inject fault while probing kunit-example-test.ko, if kzalloc fails
in kunit_parse_glob_filter(), strcpy() or strncpy() to NULL will
cause below null-ptr-deref bug. So check NULL for kzalloc() and
return int instead of void for kunit_parse_glob_filter().

 Unable to handle kernel paging request at virtual address dfff800000000000
 KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
 Mem abort info:
   ESR = 0x0000000096000005
   EC = 0x25: DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
   FSC = 0x05: level 1 translation fault
 Data abort info:
   ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
 [dfff800000000000] address between user and kernel address ranges
 Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
 Modules linked in: kunit_example_test cfg80211 rfkill 8021q garp mrp stp llc ipv6 [last unloaded: kunit_example_test]
 CPU: 4 PID: 6047 Comm: modprobe Tainted: G        W        N 6.5.0-next-20230829+ Rust-for-Linux#141
 Hardware name: linux,dummy-virt (DT)
 pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : strncpy+0x58/0xc0
 lr : kunit_filter_suites+0x15c/0xa84
 sp : ffff800082a17420
 x29: ffff800082a17420 x28: 0000000000000000 x27: 0000000000000004
 x26: 0000000000000000 x25: ffffa847e40a5320 x24: 0000000000000001
 x23: 0000000000000000 x22: 0000000000000001 x21: dfff800000000000
 x20: 000000000000002a x19: 0000000000000000 x18: 00000000750b3b54
 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
 x14: 0000000000000000 x13: 34393178302f3039 x12: ffff7508fcea4ec1
 x11: 1ffff508fcea4ec0 x10: ffff7508fcea4ec0 x9 : dfff800000000000
 x8 : ffff6051b1a7f86a x7 : ffff800082a17270 x6 : 0000000000000002
 x5 : 0000000000000098 x4 : ffff028d9817b250 x3 : 0000000000000000
 x2 : 0000000000000000 x1 : ffffa847e40a5320 x0 : 0000000000000000
 Call trace:
  strncpy+0x58/0xc0
  kunit_filter_suites+0x15c/0xa84
  kunit_module_notify+0x1b0/0x3ac
  blocking_notifier_call_chain+0xc4/0x128
  do_init_module+0x250/0x594
  load_module+0x37b0/0x44b4
  init_module_from_file+0xd4/0x128
  idempotent_init_module+0x2c8/0x524
  __arm64_sys_finit_module+0xac/0x100
  invoke_syscall+0x6c/0x258
  el0_svc_common.constprop.0+0x160/0x22c
  do_el0_svc+0x44/0x5c
  el0_svc+0x38/0x78
  el0t_64_sync_handler+0x13c/0x158
  el0t_64_sync+0x190/0x194
 Code: 5400028a d343fe63 12000a62 39400034 (38f56863)
 ---[ end trace 0000000000000000 ]---
 Kernel panic - not syncing: Oops: Fatal exception
 SMP: stopping secondary CPUs
 Kernel Offset: 0x284761400000 from 0xffff800080000000
 PHYS_OFFSET: 0xfffffd7380000000
 CPU features: 0x88000203,3c020000,1000421b
 Memory Limit: none
 Rebooting in 1 seconds..

Fixes: a127b15 ("kunit: tool: allow filtering test cases via glob")
Signed-off-by: Jinjie Ruan <[email protected]>
Reviewed-by: Rae Moar <[email protected]>
Reviewed-by: David Gow <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
If *any* object of a certain WW mutex class is locked, lockdep will
consider *all* mutexes of that class as locked. Also the lock allocation
tracking code will apparently register only the address of the first
mutex of a given class locked in a sequence.
This has the odd consequence that if that first mutex is unlocked while
other mutexes of the same class remain locked and then its memory then
freed, the lock alloc tracking code will incorrectly assume that memory
is freed with a held lock in there.

For now, work around that for drm_exec by releasing the first grabbed
object lock last.

v2:
- Fix a typo (Danilo Krummrich)
- Reword the commit message a bit.
- Add a Fixes: tag

Related lock alloc tracking warning:
[  322.660067] =========================
[  322.660070] WARNING: held lock freed!
[  322.660074] 6.5.0-rc7+ Rust-for-Linux#155 Tainted: G     U           N
[  322.660078] -------------------------
[  322.660081] kunit_try_catch/4981 is freeing memory ffff888112adc000-ffff888112adc3ff, with a lock still held there!
[  322.660089] ffff888112adc1a0 (reservation_ww_class_mutex){+.+.}-{3:3}, at: drm_exec_lock_obj+0x11a/0x600 [drm_exec]
[  322.660104] 2 locks held by kunit_try_catch/4981:
[  322.660108]  #0: ffffc9000343fe18 (reservation_ww_class_acquire){+.+.}-{0:0}, at: test_early_put+0x22f/0x490 [drm_exec_test]
[  322.660123]  #1: ffff888112adc1a0 (reservation_ww_class_mutex){+.+.}-{3:3}, at: drm_exec_lock_obj+0x11a/0x600 [drm_exec]
[  322.660135]
               stack backtrace:
[  322.660139] CPU: 7 PID: 4981 Comm: kunit_try_catch Tainted: G     U           N 6.5.0-rc7+ Rust-for-Linux#155
[  322.660146] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 0403 01/26/2021
[  322.660152] Call Trace:
[  322.660155]  <TASK>
[  322.660158]  dump_stack_lvl+0x57/0x90
[  322.660164]  debug_check_no_locks_freed+0x20b/0x2b0
[  322.660172]  slab_free_freelist_hook+0xa1/0x160
[  322.660179]  ? drm_exec_unlock_all+0x168/0x2a0 [drm_exec]
[  322.660186]  __kmem_cache_free+0xb2/0x290
[  322.660192]  drm_exec_unlock_all+0x168/0x2a0 [drm_exec]
[  322.660200]  drm_exec_fini+0xf/0x1c0 [drm_exec]
[  322.660206]  test_early_put+0x289/0x490 [drm_exec_test]
[  322.660215]  ? __pfx_test_early_put+0x10/0x10 [drm_exec_test]
[  322.660222]  ? __kasan_check_byte+0xf/0x40
[  322.660227]  ? __ksize+0x63/0x140
[  322.660233]  ? drmm_add_final_kfree+0x3e/0xa0 [drm]
[  322.660289]  ? _raw_spin_unlock_irqrestore+0x30/0x60
[  322.660294]  ? lockdep_hardirqs_on+0x7d/0x100
[  322.660301]  ? __pfx_kunit_try_run_case+0x10/0x10 [kunit]
[  322.660310]  ? __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10 [kunit]
[  322.660319]  kunit_generic_run_threadfn_adapter+0x4a/0x90 [kunit]
[  322.660328]  kthread+0x2e7/0x3c0
[  322.660334]  ? __pfx_kthread+0x10/0x10
[  322.660339]  ret_from_fork+0x2d/0x70
[  322.660345]  ? __pfx_kthread+0x10/0x10
[  322.660349]  ret_from_fork_asm+0x1b/0x30
[  322.660358]  </TASK>
[  322.660818]     ok 8 test_early_put

Cc: Christian König <[email protected]>
Cc: Boris Brezillon <[email protected]>
Cc: Danilo Krummrich <[email protected]>
Cc: [email protected]
Fixes: 0959321 ("drm: execution context for GEM buffers v7")
Signed-off-by: Thomas Hellström <[email protected]>
Reviewed-by: Boris Brezillon <[email protected]>
Reviewed-by: Danilo Krummrich <[email protected]>
Reviewed-by: Christian König <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
During the ino lookup ioctl we can end up calling btrfs_iget() to get an
inode reference while we are holding on a root's btree. If btrfs_iget()
needs to lookup the inode from the root's btree, because it's not
currently loaded in memory, then it will need to lock another or the
same path in the same root btree. This may result in a deadlock and
trigger the following lockdep splat:

  WARNING: possible circular locking dependency detected
  6.5.0-rc7-syzkaller-00004-gf7757129e3de #0 Not tainted
  ------------------------------------------------------
  syz-executor277/5012 is trying to acquire lock:
  ffff88802df41710 (btrfs-tree-01){++++}-{3:3}, at: __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136

  but task is already holding lock:
  ffff88802df418e8 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #1 (btrfs-tree-00){++++}-{3:3}:
         down_read_nested+0x49/0x2f0 kernel/locking/rwsem.c:1645
         __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136
         btrfs_search_slot+0x13a4/0x2f80 fs/btrfs/ctree.c:2302
         btrfs_init_root_free_objectid+0x148/0x320 fs/btrfs/disk-io.c:4955
         btrfs_init_fs_root fs/btrfs/disk-io.c:1128 [inline]
         btrfs_get_root_ref+0x5ae/0xae0 fs/btrfs/disk-io.c:1338
         btrfs_get_fs_root fs/btrfs/disk-io.c:1390 [inline]
         open_ctree+0x29c8/0x3030 fs/btrfs/disk-io.c:3494
         btrfs_fill_super+0x1c7/0x2f0 fs/btrfs/super.c:1154
         btrfs_mount_root+0x7e0/0x910 fs/btrfs/super.c:1519
         legacy_get_tree+0xef/0x190 fs/fs_context.c:611
         vfs_get_tree+0x8c/0x270 fs/super.c:1519
         fc_mount fs/namespace.c:1112 [inline]
         vfs_kern_mount+0xbc/0x150 fs/namespace.c:1142
         btrfs_mount+0x39f/0xb50 fs/btrfs/super.c:1579
         legacy_get_tree+0xef/0x190 fs/fs_context.c:611
         vfs_get_tree+0x8c/0x270 fs/super.c:1519
         do_new_mount+0x28f/0xae0 fs/namespace.c:3335
         do_mount fs/namespace.c:3675 [inline]
         __do_sys_mount fs/namespace.c:3884 [inline]
         __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3861
         do_syscall_x64 arch/x86/entry/common.c:50 [inline]
         do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
         entry_SYSCALL_64_after_hwframe+0x63/0xcd

  -> #0 (btrfs-tree-01){++++}-{3:3}:
         check_prev_add kernel/locking/lockdep.c:3142 [inline]
         check_prevs_add kernel/locking/lockdep.c:3261 [inline]
         validate_chain kernel/locking/lockdep.c:3876 [inline]
         __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5144
         lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5761
         down_read_nested+0x49/0x2f0 kernel/locking/rwsem.c:1645
         __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136
         btrfs_tree_read_lock fs/btrfs/locking.c:142 [inline]
         btrfs_read_lock_root_node+0x292/0x3c0 fs/btrfs/locking.c:281
         btrfs_search_slot_get_root fs/btrfs/ctree.c:1832 [inline]
         btrfs_search_slot+0x4ff/0x2f80 fs/btrfs/ctree.c:2154
         btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:412
         btrfs_read_locked_inode fs/btrfs/inode.c:3892 [inline]
         btrfs_iget_path+0x2d9/0x1520 fs/btrfs/inode.c:5716
         btrfs_search_path_in_tree_user fs/btrfs/ioctl.c:1961 [inline]
         btrfs_ioctl_ino_lookup_user+0x77a/0xf50 fs/btrfs/ioctl.c:2105
         btrfs_ioctl+0xb0b/0xd40 fs/btrfs/ioctl.c:4683
         vfs_ioctl fs/ioctl.c:51 [inline]
         __do_sys_ioctl fs/ioctl.c:870 [inline]
         __se_sys_ioctl+0xf8/0x170 fs/ioctl.c:856
         do_syscall_x64 arch/x86/entry/common.c:50 [inline]
         do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
         entry_SYSCALL_64_after_hwframe+0x63/0xcd

  other info that might help us debug this:

   Possible unsafe locking scenario:

         CPU0                    CPU1
         ----                    ----
    rlock(btrfs-tree-00);
                                 lock(btrfs-tree-01);
                                 lock(btrfs-tree-00);
    rlock(btrfs-tree-01);

   *** DEADLOCK ***

  1 lock held by syz-executor277/5012:
   #0: ffff88802df418e8 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136

  stack backtrace:
  CPU: 1 PID: 5012 Comm: syz-executor277 Not tainted 6.5.0-rc7-syzkaller-00004-gf7757129e3de #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
  Call Trace:
   <TASK>
   __dump_stack lib/dump_stack.c:88 [inline]
   dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
   check_noncircular+0x375/0x4a0 kernel/locking/lockdep.c:2195
   check_prev_add kernel/locking/lockdep.c:3142 [inline]
   check_prevs_add kernel/locking/lockdep.c:3261 [inline]
   validate_chain kernel/locking/lockdep.c:3876 [inline]
   __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5144
   lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5761
   down_read_nested+0x49/0x2f0 kernel/locking/rwsem.c:1645
   __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136
   btrfs_tree_read_lock fs/btrfs/locking.c:142 [inline]
   btrfs_read_lock_root_node+0x292/0x3c0 fs/btrfs/locking.c:281
   btrfs_search_slot_get_root fs/btrfs/ctree.c:1832 [inline]
   btrfs_search_slot+0x4ff/0x2f80 fs/btrfs/ctree.c:2154
   btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:412
   btrfs_read_locked_inode fs/btrfs/inode.c:3892 [inline]
   btrfs_iget_path+0x2d9/0x1520 fs/btrfs/inode.c:5716
   btrfs_search_path_in_tree_user fs/btrfs/ioctl.c:1961 [inline]
   btrfs_ioctl_ino_lookup_user+0x77a/0xf50 fs/btrfs/ioctl.c:2105
   btrfs_ioctl+0xb0b/0xd40 fs/btrfs/ioctl.c:4683
   vfs_ioctl fs/ioctl.c:51 [inline]
   __do_sys_ioctl fs/ioctl.c:870 [inline]
   __se_sys_ioctl+0xf8/0x170 fs/ioctl.c:856
   do_syscall_x64 arch/x86/entry/common.c:50 [inline]
   do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
   entry_SYSCALL_64_after_hwframe+0x63/0xcd
  RIP: 0033:0x7f0bec94ea39

Fix this simply by releasing the path before calling btrfs_iget() as at
point we don't need the path anymore.

Reported-by: [email protected]
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Fixes: 23d0b79 ("btrfs: Add unprivileged version of ino_lookup ioctl")
CC: [email protected] # 4.19+
Reviewed-by: Josef Bacik <[email protected]>
Signed-off-by: Filipe Manana <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
… delayed items

When running delayed items we are holding a delayed node's mutex and then
we will attempt to modify a subvolume btree to insert/update/delete the
delayed items. However if have an error during the insertions for example,
btrfs_insert_delayed_items() may return with a path that has locked extent
buffers (a leaf at the very least), and then we attempt to release the
delayed node at __btrfs_run_delayed_items(), which requires taking the
delayed node's mutex, causing an ABBA type of deadlock. This was reported
by syzbot and the lockdep splat is the following:

  WARNING: possible circular locking dependency detected
  6.5.0-rc7-syzkaller-00024-g93f5de5f648d #0 Not tainted
  ------------------------------------------------------
  syz-executor.2/13257 is trying to acquire lock:
  ffff88801835c0c0 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node+0x9a/0xaa0 fs/btrfs/delayed-inode.c:256

  but task is already holding lock:
  ffff88802a5ab8e8 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_lock+0x3c/0x2a0 fs/btrfs/locking.c:198

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #1 (btrfs-tree-00){++++}-{3:3}:
         __lock_release kernel/locking/lockdep.c:5475 [inline]
         lock_release+0x36f/0x9d0 kernel/locking/lockdep.c:5781
         up_write+0x79/0x580 kernel/locking/rwsem.c:1625
         btrfs_tree_unlock_rw fs/btrfs/locking.h:189 [inline]
         btrfs_unlock_up_safe+0x179/0x3b0 fs/btrfs/locking.c:239
         search_leaf fs/btrfs/ctree.c:1986 [inline]
         btrfs_search_slot+0x2511/0x2f80 fs/btrfs/ctree.c:2230
         btrfs_insert_empty_items+0x9c/0x180 fs/btrfs/ctree.c:4376
         btrfs_insert_delayed_item fs/btrfs/delayed-inode.c:746 [inline]
         btrfs_insert_delayed_items fs/btrfs/delayed-inode.c:824 [inline]
         __btrfs_commit_inode_delayed_items+0xd24/0x2410 fs/btrfs/delayed-inode.c:1111
         __btrfs_run_delayed_items+0x1db/0x430 fs/btrfs/delayed-inode.c:1153
         flush_space+0x269/0xe70 fs/btrfs/space-info.c:723
         btrfs_async_reclaim_metadata_space+0x106/0x350 fs/btrfs/space-info.c:1078
         process_one_work+0x92c/0x12c0 kernel/workqueue.c:2600
         worker_thread+0xa63/0x1210 kernel/workqueue.c:2751
         kthread+0x2b8/0x350 kernel/kthread.c:389
         ret_from_fork+0x2e/0x60 arch/x86/kernel/process.c:145
         ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

  -> #0 (&delayed_node->mutex){+.+.}-{3:3}:
         check_prev_add kernel/locking/lockdep.c:3142 [inline]
         check_prevs_add kernel/locking/lockdep.c:3261 [inline]
         validate_chain kernel/locking/lockdep.c:3876 [inline]
         __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5144
         lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5761
         __mutex_lock_common+0x1d8/0x2530 kernel/locking/mutex.c:603
         __mutex_lock kernel/locking/mutex.c:747 [inline]
         mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799
         __btrfs_release_delayed_node+0x9a/0xaa0 fs/btrfs/delayed-inode.c:256
         btrfs_release_delayed_node fs/btrfs/delayed-inode.c:281 [inline]
         __btrfs_run_delayed_items+0x2b5/0x430 fs/btrfs/delayed-inode.c:1156
         btrfs_commit_transaction+0x859/0x2ff0 fs/btrfs/transaction.c:2276
         btrfs_sync_file+0xf56/0x1330 fs/btrfs/file.c:1988
         vfs_fsync_range fs/sync.c:188 [inline]
         vfs_fsync fs/sync.c:202 [inline]
         do_fsync fs/sync.c:212 [inline]
         __do_sys_fsync fs/sync.c:220 [inline]
         __se_sys_fsync fs/sync.c:218 [inline]
         __x64_sys_fsync+0x196/0x1e0 fs/sync.c:218
         do_syscall_x64 arch/x86/entry/common.c:50 [inline]
         do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
         entry_SYSCALL_64_after_hwframe+0x63/0xcd

  other info that might help us debug this:

   Possible unsafe locking scenario:

         CPU0                    CPU1
         ----                    ----
    lock(btrfs-tree-00);
                                 lock(&delayed_node->mutex);
                                 lock(btrfs-tree-00);
    lock(&delayed_node->mutex);

   *** DEADLOCK ***

  3 locks held by syz-executor.2/13257:
   #0: ffff88802c1ee370 (btrfs_trans_num_writers){++++}-{0:0}, at: spin_unlock include/linux/spinlock.h:391 [inline]
   #0: ffff88802c1ee370 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0xb87/0xe00 fs/btrfs/transaction.c:287
   #1: ffff88802c1ee398 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0xbb2/0xe00 fs/btrfs/transaction.c:288
   Rust-for-Linux#2: ffff88802a5ab8e8 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_lock+0x3c/0x2a0 fs/btrfs/locking.c:198

  stack backtrace:
  CPU: 0 PID: 13257 Comm: syz-executor.2 Not tainted 6.5.0-rc7-syzkaller-00024-g93f5de5f648d #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
  Call Trace:
   <TASK>
   __dump_stack lib/dump_stack.c:88 [inline]
   dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
   check_noncircular+0x375/0x4a0 kernel/locking/lockdep.c:2195
   check_prev_add kernel/locking/lockdep.c:3142 [inline]
   check_prevs_add kernel/locking/lockdep.c:3261 [inline]
   validate_chain kernel/locking/lockdep.c:3876 [inline]
   __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5144
   lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5761
   __mutex_lock_common+0x1d8/0x2530 kernel/locking/mutex.c:603
   __mutex_lock kernel/locking/mutex.c:747 [inline]
   mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799
   __btrfs_release_delayed_node+0x9a/0xaa0 fs/btrfs/delayed-inode.c:256
   btrfs_release_delayed_node fs/btrfs/delayed-inode.c:281 [inline]
   __btrfs_run_delayed_items+0x2b5/0x430 fs/btrfs/delayed-inode.c:1156
   btrfs_commit_transaction+0x859/0x2ff0 fs/btrfs/transaction.c:2276
   btrfs_sync_file+0xf56/0x1330 fs/btrfs/file.c:1988
   vfs_fsync_range fs/sync.c:188 [inline]
   vfs_fsync fs/sync.c:202 [inline]
   do_fsync fs/sync.c:212 [inline]
   __do_sys_fsync fs/sync.c:220 [inline]
   __se_sys_fsync fs/sync.c:218 [inline]
   __x64_sys_fsync+0x196/0x1e0 fs/sync.c:218
   do_syscall_x64 arch/x86/entry/common.c:50 [inline]
   do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
   entry_SYSCALL_64_after_hwframe+0x63/0xcd
  RIP: 0033:0x7f3ad047cae9
  Code: 28 00 00 00 75 (...)
  RSP: 002b:00007f3ad12510c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004a
  RAX: ffffffffffffffda RBX: 00007f3ad059bf80 RCX: 00007f3ad047cae9
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
  RBP: 00007f3ad04c847a R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
  R13: 000000000000000b R14: 00007f3ad059bf80 R15: 00007ffe56af92f8
   </TASK>
  ------------[ cut here ]------------

Fix this by releasing the path before releasing the delayed node in the
error path at __btrfs_run_delayed_items().

Reported-by: [email protected]
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
CC: [email protected] # 4.14+
Signed-off-by: Filipe Manana <[email protected]>
Signed-off-by: David Sterba <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
…n smcr_port_add

While doing smcr_port_add, there maybe linkgroup add into or delete
from smc_lgr_list.list at the same time, which may result kernel crash.
So, use smc_lgr_list.lock to protect smc_lgr_list.list iterate in
smcr_port_add.

The crash calltrace show below:
BUG: kernel NULL pointer dereference, address: 0000000000000000
PGD 0 P4D 0
Oops: 0000 [#1] SMP NOPTI
CPU: 0 PID: 559726 Comm: kworker/0:92 Kdump: loaded Tainted: G
Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 449e491 04/01/2014
Workqueue: events smc_ib_port_event_work [smc]
RIP: 0010:smcr_port_add+0xa6/0xf0 [smc]
RSP: 0000:ffffa5a2c8f67de0 EFLAGS: 00010297
RAX: 0000000000000001 RBX: ffff9935e0650000 RCX: 0000000000000000
RDX: 0000000000000010 RSI: ffff9935e0654290 RDI: ffff9935c8560000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffff9934c0401918
R10: 0000000000000000 R11: ffffffffb4a5c278 R12: ffff99364029aae4
R13: ffff99364029aa00 R14: 00000000ffffffed R15: ffff99364029ab08
FS:  0000000000000000(0000) GS:ffff994380600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000f06a10003 CR4: 0000000002770ef0
PKRU: 55555554
Call Trace:
 smc_ib_port_event_work+0x18f/0x380 [smc]
 process_one_work+0x19b/0x340
 worker_thread+0x30/0x370
 ? process_one_work+0x340/0x340
 kthread+0x114/0x130
 ? __kthread_cancel_work+0x50/0x50
 ret_from_fork+0x1f/0x30

Fixes: 1f90a05 ("net/smc: add smcr_port_add() and smcr_link_up() processing")
Signed-off-by: Guangguan Wang <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
…roy()

After the commit in Fixes:, if a module that created a slab cache does not
release all of its allocated objects before destroying the cache (at rmmod
time), we might end up releasing the kmem_cache object without removing it
from the slab_caches list thus corrupting the list as kmem_cache_destroy()
ignores the return value from shutdown_cache(), which in turn never removes
the kmem_cache object from slabs_list in case __kmem_cache_shutdown() fails
to release all of the cache's slabs.

This is easily observable on a kernel built with CONFIG_DEBUG_LIST=y
as after that ill release the system will immediately trip on list_add,
or list_del, assertions similar to the one shown below as soon as another
kmem_cache gets created, or destroyed:

  [ 1041.213632] list_del corruption. next->prev should be ffff89f596fb5768, but was 52f1e5016aeee75d. (next=ffff89f595a1b268)
  [ 1041.219165] ------------[ cut here ]------------
  [ 1041.221517] kernel BUG at lib/list_debug.c:62!
  [ 1041.223452] invalid opcode: 0000 [#1] PREEMPT SMP PTI
  [ 1041.225408] CPU: 2 PID: 1852 Comm: rmmod Kdump: loaded Tainted: G    B   W  OE      6.5.0 Rust-for-Linux#15
  [ 1041.228244] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS edk2-20230524-3.fc37 05/24/2023
  [ 1041.231212] RIP: 0010:__list_del_entry_valid+0xae/0xb0

Another quick way to trigger this issue, in a kernel with CONFIG_SLUB=y,
is to set slub_debug to poison the released objects and then just run
cat /proc/slabinfo after removing the module that leaks slab objects,
in which case the kernel will panic:

  [   50.954843] general protection fault, probably for non-canonical address 0xa56b6b6b6b6b6b8b: 0000 [#1] PREEMPT SMP PTI
  [   50.961545] CPU: 2 PID: 1495 Comm: cat Kdump: loaded Tainted: G    B   W  OE      6.5.0 Rust-for-Linux#15
  [   50.966808] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS edk2-20230524-3.fc37 05/24/2023
  [   50.972663] RIP: 0010:get_slabinfo+0x42/0xf0

This patch fixes this issue by properly checking shutdown_cache()'s
return value before taking the kmem_cache_release() branch.

Fixes: 0495e33 ("mm/slab_common: Deleting kobject in kmem_cache_destroy() without holding slab_mutex/cpu_hotplug_lock")
Signed-off-by: Rafael Aquini <[email protected]>
Cc: [email protected]
Reviewed-by: Waiman Long <[email protected]>
Signed-off-by: Vlastimil Babka <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
Hou Tao says:

====================
Fix the unmatched unit_size of bpf_mem_cache

From: Hou Tao <[email protected]>

Hi,

The patchset aims to fix the reported warning [0] when the unit_size of
bpf_mem_cache is mismatched with the object size of underly slab-cache.

Patch #1 fixes the warning by adjusting size_index according to the
value of KMALLOC_MIN_SIZE, so bpf_mem_cache with unit_size which is
smaller than KMALLOC_MIN_SIZE or is not aligned with KMALLOC_MIN_SIZE
will be redirected to bpf_mem_cache with bigger unit_size. Patch Rust-for-Linux#2
doesn't do prefill for these redirected bpf_mem_cache to save memory.
Patch Rust-for-Linux#3 adds further error check in bpf_mem_alloc_init() to ensure the
unit_size and object_size are always matched and to prevent potential
issues due to the mismatch.

Please see individual patches for more details. And comments are always
welcome.

[0]: https://lore.kernel.org/bpf/[email protected]
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
macb_set_tx_clk() is called under a spinlock but itself calls clk_set_rate()
which can sleep. This results in:

| BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
| pps pps1: new PPS source ptp1
| in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 40, name: kworker/u4:3
| preempt_count: 1, expected: 0
| RCU nest depth: 0, expected: 0
| 4 locks held by kworker/u4:3/40:
|  #0: ffff000003409148
| macb ff0c000.ethernet: gem-ptp-timer ptp clock registered.
|  ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x14c/0x51c
|  #1: ffff8000833cbdd8 ((work_completion)(&pl->resolve)){+.+.}-{0:0}, at: process_one_work+0x14c/0x51c
|  Rust-for-Linux#2: ffff000004f01578 (&pl->state_mutex){+.+.}-{4:4}, at: phylink_resolve+0x44/0x4e8
|  Rust-for-Linux#3: ffff000004f06f50 (&bp->lock){....}-{3:3}, at: macb_mac_link_up+0x40/0x2ac
| irq event stamp: 113998
| hardirqs last  enabled at (113997): [<ffff800080e8503c>] _raw_spin_unlock_irq+0x30/0x64
| hardirqs last disabled at (113998): [<ffff800080e84478>] _raw_spin_lock_irqsave+0xac/0xc8
| softirqs last  enabled at (113608): [<ffff800080010630>] __do_softirq+0x430/0x4e4
| softirqs last disabled at (113597): [<ffff80008001614c>] ____do_softirq+0x10/0x1c
| CPU: 0 PID: 40 Comm: kworker/u4:3 Not tainted 6.5.0-11717-g9355ce8b2f50-dirty Rust-for-Linux#368
| Hardware name: ... ZynqMP ... (DT)
| Workqueue: events_power_efficient phylink_resolve
| Call trace:
|  dump_backtrace+0x98/0xf0
|  show_stack+0x18/0x24
|  dump_stack_lvl+0x60/0xac
|  dump_stack+0x18/0x24
|  __might_resched+0x144/0x24c
|  __might_sleep+0x48/0x98
|  __mutex_lock+0x58/0x7b0
|  mutex_lock_nested+0x24/0x30
|  clk_prepare_lock+0x4c/0xa8
|  clk_set_rate+0x24/0x8c
|  macb_mac_link_up+0x25c/0x2ac
|  phylink_resolve+0x178/0x4e8
|  process_one_work+0x1ec/0x51c
|  worker_thread+0x1ec/0x3e4
|  kthread+0x120/0x124
|  ret_from_fork+0x10/0x20

The obvious fix is to move the call to macb_set_tx_clk() out of the
protected area. This seems safe as rx and tx are both disabled anyway at
this point.
It is however not entirely clear what the spinlock shall protect. It
could be the read-modify-write access to the NCFGR register, but this
is accessed in macb_set_rx_mode() and macb_set_rxcsum_feature() as well
without holding the spinlock. It could also be the register accesses
done in mog_init_rings() or macb_init_buffers(), but again these
functions are called without holding the spinlock in macb_hresp_error_task().
The locking seems fishy in this driver and it might deserve another look
before this patch is applied.

Fixes: 633e98a ("net: macb: use resolved link config in mac_link_up()")
Signed-off-by: Sascha Hauer <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
Inject fault while probing btrfs.ko, if kstrdup() fails in
eventfs_prepare_ef() in eventfs_add_dir(), it will return ERR_PTR
to assign file->ef. But the eventfs_remove() check NULL in
trace_module_remove_events(), which causes the below NULL
pointer dereference.

As both Masami and Steven suggest, allocater side should handle the
error carefully and remove it, so fix the places where it failed.

 Could not create tracefs 'raid56_write' directory
 Btrfs loaded, zoned=no, fsverity=no
 Unable to handle kernel NULL pointer dereference at virtual address 000000000000001c
 Mem abort info:
   ESR = 0x0000000096000004
   EC = 0x25: DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
   FSC = 0x04: level 0 translation fault
 Data abort info:
   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
 user pgtable: 4k pages, 48-bit VAs, pgdp=0000000102544000
 [000000000000001c] pgd=0000000000000000, p4d=0000000000000000
 Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
 Dumping ftrace buffer:
    (ftrace buffer empty)
 Modules linked in: btrfs(-) libcrc32c xor xor_neon raid6_pq cfg80211 rfkill 8021q garp mrp stp llc ipv6 [last unloaded: btrfs]
 CPU: 15 PID: 1343 Comm: rmmod Tainted: G                 N 6.5.0+ Rust-for-Linux#40
 Hardware name: linux,dummy-virt (DT)
 pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : eventfs_remove_rec+0x24/0xc0
 lr : eventfs_remove+0x68/0x1d8
 sp : ffff800082d63b60
 x29: ffff800082d63b60 x28: ffffb84b80ddd00c x27: ffffb84b3054ba40
 x26: 0000000000000002 x25: ffff800082d63bf8 x24: ffffb84b8398e440
 x23: ffffb84b82af3000 x22: dead000000000100 x21: dead000000000122
 x20: ffff800082d63bf8 x19: fffffffffffffff4 x18: ffffb84b82508820
 x17: 0000000000000000 x16: 0000000000000000 x15: 000083bc876a3166
 x14: 000000000000006d x13: 000000000000006d x12: 0000000000000000
 x11: 0000000000000001 x10: 00000000000017e0 x9 : 0000000000000001
 x8 : 0000000000000000 x7 : 0000000000000000 x6 : ffffb84b84289804
 x5 : 0000000000000000 x4 : 9696969696969697 x3 : ffff33a5b7601f38
 x2 : 0000000000000000 x1 : ffff800082d63bf8 x0 : fffffffffffffff4
 Call trace:
  eventfs_remove_rec+0x24/0xc0
  eventfs_remove+0x68/0x1d8
  remove_event_file_dir+0x88/0x100
  event_remove+0x140/0x15c
  trace_module_notify+0x1fc/0x230
  notifier_call_chain+0x98/0x17c
  blocking_notifier_call_chain+0x4c/0x74
  __arm64_sys_delete_module+0x1a4/0x298
  invoke_syscall+0x44/0x100
  el0_svc_common.constprop.1+0x68/0xe0
  do_el0_svc+0x1c/0x28
  el0_svc+0x3c/0xc4
  el0t_64_sync_handler+0xa0/0xc4
  el0t_64_sync+0x174/0x178
 Code: 5400052c a90153b3 aa0003f3 aa0103f4 (f9401400)
 ---[ end trace 0000000000000000 ]---
 Kernel panic - not syncing: Oops: Fatal exception
 SMP: stopping secondary CPUs
 Dumping ftrace buffer:
    (ftrace buffer empty)
 Kernel Offset: 0x384b00c00000 from 0xffff800080000000
 PHYS_OFFSET: 0xffffcc5b80000000
 CPU features: 0x88000203,3c020000,1000421b
 Memory Limit: none
 Rebooting in 1 seconds..

Link: https://lore.kernel.org/linux-trace-kernel/[email protected]
Link: https://lore.kernel.org/all/[email protected]/
Link: https://lore.kernel.org/all/[email protected]/
Link: https://lore.kernel.org/all/[email protected]/
Link: https://lore.kernel.org/all/[email protected]/

Cc: Ajay Kaher <[email protected]>
Fixes: 5bdcd5f ("eventfs: Implement removal of meta data from eventfs")
Signed-off-by: Jinjie Ruan <[email protected]>
Suggested-by: Masami Hiramatsu (Google) <[email protected]>
Suggested-by: Steven Rostedt <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
Harshit Mogalapalli slogged through several reports from our internal
syzbot instance and observed that they all had a common stack trace:

BUG: KASAN: user-memory-access in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: user-memory-access in atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1294 [inline]
BUG: KASAN: user-memory-access in queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
BUG: KASAN: user-memory-access in do_raw_spin_lock include/linux/spinlock.h:187 [inline]
BUG: KASAN: user-memory-access in __raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline]
BUG: KASAN: user-memory-access in _raw_spin_lock+0x76/0xe0 kernel/locking/spinlock.c:154
Write of size 4 at addr 0000001dd87ee280 by task syz-executor365/1543

CPU: 2 PID: 1543 Comm: syz-executor365 Not tainted 6.5.0-syzk #1
Hardware name: Red Hat KVM, BIOS 1.13.0-2.module+el8.3.0+7860+a7792d29 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x83/0xb0 lib/dump_stack.c:106
 print_report+0x3f8/0x620 mm/kasan/report.c:478
 kasan_report+0xb0/0xe0 mm/kasan/report.c:588
 check_region_inline mm/kasan/generic.c:181 [inline]
 kasan_check_range+0x139/0x1e0 mm/kasan/generic.c:187
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1294 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
 do_raw_spin_lock include/linux/spinlock.h:187 [inline]
 __raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline]
 _raw_spin_lock+0x76/0xe0 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 xchk_stats_merge_one.isra.1+0x39/0x650 fs/xfs/scrub/stats.c:191
 xchk_stats_merge+0x5f/0xe0 fs/xfs/scrub/stats.c:225
 xfs_scrub_metadata+0x252/0x14e0 fs/xfs/scrub/scrub.c:599
 xfs_ioc_scrub_metadata+0xc8/0x160 fs/xfs/xfs_ioctl.c:1646
 xfs_file_ioctl+0x3fd/0x1870 fs/xfs/xfs_ioctl.c:1955
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl fs/ioctl.c:857 [inline]
 __x64_sys_ioctl+0x199/0x220 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3e/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8
RIP: 0033:0x7ff155af753d
Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1b 79 2c 00 f7 d8 64 89 01 48
RSP: 002b:00007ffc006e2568 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff155af753d
RDX: 00000000200000c0 RSI: 00000000c040583c RDI: 0000000000000003
RBP: 00000000ffffffff R08: 00000000004010c0 R09: 00000000004010c0
R10: 00000000004010c0 R11: 0000000000000246 R12: 0000000000400cb0
R13: 00007ffc006e2670 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

The root cause here is that xchk_stats_merge_one walks off the end of
the xchk_scrub_stats.cs_stats array because it has been fed a garbage
value in sm->sm_type.  That occurs because I put the xchk_stats_merge
in the wrong place -- it should have been after the last xchk_teardown
call on our way out of xfs_scrub_metadata because we only call the
teardown function if we called the setup function, and we don't call the
setup functions if the inputs are obviously garbage.

Thanks to Harshit for triaging the bug reports and bringing this to my
attention.

Fixes: d7a74ca ("xfs: track usage statistics of online fsck")
Reported-by: Harshit Mogalapalli <[email protected]>
Signed-off-by: Darrick J. Wong <[email protected]>
Reviewed-by: Dave Chinner <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
…kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.6, take #1

- Fix EL2 Stage-1 MMIO mappings where a random address was used

- Fix SMCCC function number comparison when the SVE hint is set
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
When opening a directory (opendir(3)) or rewinding it (rewinddir(3)), we
are not holding the directory's inode locked, and this can result in later
attempting to add two entries to the directory with the same index number,
resulting in a transaction abort, with -EEXIST (-17), when inserting the
second delayed dir index. This results in a trace like the following:

  Sep 11 22:34:59 myhostname kernel: BTRFS error (device dm-3): err add delayed dir index item(name: cockroach-stderr.log) into the insertion tree of the delayed node(root id: 5, inode id: 4539217, errno: -17)
  Sep 11 22:34:59 myhostname kernel: ------------[ cut here ]------------
  Sep 11 22:34:59 myhostname kernel: kernel BUG at fs/btrfs/delayed-inode.c:1504!
  Sep 11 22:34:59 myhostname kernel: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
  Sep 11 22:34:59 myhostname kernel: CPU: 0 PID: 7159 Comm: cockroach Not tainted 6.4.15-200.fc38.x86_64 #1
  Sep 11 22:34:59 myhostname kernel: Hardware name: ASUS ESC500 G3/P9D WS, BIOS 2402 06/27/2018
  Sep 11 22:34:59 myhostname kernel: RIP: 0010:btrfs_insert_delayed_dir_index+0x1da/0x260
  Sep 11 22:34:59 myhostname kernel: Code: eb dd 48 (...)
  Sep 11 22:34:59 myhostname kernel: RSP: 0000:ffffa9980e0fbb28 EFLAGS: 00010282
  Sep 11 22:34:59 myhostname kernel: RAX: 0000000000000000 RBX: ffff8b10b8f4a3c0 RCX: 0000000000000000
  Sep 11 22:34:59 myhostname kernel: RDX: 0000000000000000 RSI: ffff8b177ec21540 RDI: ffff8b177ec21540
  Sep 11 22:34:59 myhostname kernel: RBP: ffff8b110cf80888 R08: 0000000000000000 R09: ffffa9980e0fb938
  Sep 11 22:34:59 myhostname kernel: R10: 0000000000000003 R11: ffffffff86146508 R12: 0000000000000014
  Sep 11 22:34:59 myhostname kernel: R13: ffff8b1131ae5b40 R14: ffff8b10b8f4a418 R15: 00000000ffffffef
  Sep 11 22:34:59 myhostname kernel: FS:  00007fb14a7fe6c0(0000) GS:ffff8b177ec00000(0000) knlGS:0000000000000000
  Sep 11 22:34:59 myhostname kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  Sep 11 22:34:59 myhostname kernel: CR2: 000000c00143d000 CR3: 00000001b3b4e002 CR4: 00000000001706f0
  Sep 11 22:34:59 myhostname kernel: Call Trace:
  Sep 11 22:34:59 myhostname kernel:  <TASK>
  Sep 11 22:34:59 myhostname kernel:  ? die+0x36/0x90
  Sep 11 22:34:59 myhostname kernel:  ? do_trap+0xda/0x100
  Sep 11 22:34:59 myhostname kernel:  ? btrfs_insert_delayed_dir_index+0x1da/0x260
  Sep 11 22:34:59 myhostname kernel:  ? do_error_trap+0x6a/0x90
  Sep 11 22:34:59 myhostname kernel:  ? btrfs_insert_delayed_dir_index+0x1da/0x260
  Sep 11 22:34:59 myhostname kernel:  ? exc_invalid_op+0x50/0x70
  Sep 11 22:34:59 myhostname kernel:  ? btrfs_insert_delayed_dir_index+0x1da/0x260
  Sep 11 22:34:59 myhostname kernel:  ? asm_exc_invalid_op+0x1a/0x20
  Sep 11 22:34:59 myhostname kernel:  ? btrfs_insert_delayed_dir_index+0x1da/0x260
  Sep 11 22:34:59 myhostname kernel:  ? btrfs_insert_delayed_dir_index+0x1da/0x260
  Sep 11 22:34:59 myhostname kernel:  btrfs_insert_dir_item+0x200/0x280
  Sep 11 22:34:59 myhostname kernel:  btrfs_add_link+0xab/0x4f0
  Sep 11 22:34:59 myhostname kernel:  ? ktime_get_real_ts64+0x47/0xe0
  Sep 11 22:34:59 myhostname kernel:  btrfs_create_new_inode+0x7cd/0xa80
  Sep 11 22:34:59 myhostname kernel:  btrfs_symlink+0x190/0x4d0
  Sep 11 22:34:59 myhostname kernel:  ? schedule+0x5e/0xd0
  Sep 11 22:34:59 myhostname kernel:  ? __d_lookup+0x7e/0xc0
  Sep 11 22:34:59 myhostname kernel:  vfs_symlink+0x148/0x1e0
  Sep 11 22:34:59 myhostname kernel:  do_symlinkat+0x130/0x140
  Sep 11 22:34:59 myhostname kernel:  __x64_sys_symlinkat+0x3d/0x50
  Sep 11 22:34:59 myhostname kernel:  do_syscall_64+0x5d/0x90
  Sep 11 22:34:59 myhostname kernel:  ? syscall_exit_to_user_mode+0x2b/0x40
  Sep 11 22:34:59 myhostname kernel:  ? do_syscall_64+0x6c/0x90
  Sep 11 22:34:59 myhostname kernel:  entry_SYSCALL_64_after_hwframe+0x72/0xdc

The race leading to the problem happens like this:

1) Directory inode X is loaded into memory, its ->index_cnt field is
   initialized to (u64)-1 (at btrfs_alloc_inode());

2) Task A is adding a new file to directory X, holding its vfs inode lock,
   and calls btrfs_set_inode_index() to get an index number for the entry.

   Because the inode's index_cnt field is set to (u64)-1 it calls
   btrfs_inode_delayed_dir_index_count() which fails because no dir index
   entries were added yet to the delayed inode and then it calls
   btrfs_set_inode_index_count(). This functions finds the last dir index
   key and then sets index_cnt to that index value + 1. It found that the
   last index key has an offset of 100. However before it assigns a value
   of 101 to index_cnt...

3) Task B calls opendir(3), ending up at btrfs_opendir(), where the VFS
   lock for inode X is not taken, so it calls btrfs_get_dir_last_index()
   and sees index_cnt still with a value of (u64)-1. Because of that it
   calls btrfs_inode_delayed_dir_index_count() which fails since no dir
   index entries were added to the delayed inode yet, and then it also
   calls btrfs_set_inode_index_count(). This also finds that the last
   index key has an offset of 100, and before it assigns the value 101
   to the index_cnt field of inode X...

4) Task A assigns a value of 101 to index_cnt. And then the code flow
   goes to btrfs_set_inode_index() where it increments index_cnt from
   101 to 102. Task A then creates a delayed dir index entry with a
   sequence number of 101 and adds it to the delayed inode;

5) Task B assigns 101 to the index_cnt field of inode X;

6) At some later point when someone tries to add a new entry to the
   directory, btrfs_set_inode_index() will return 101 again and shortly
   after an attempt to add another delayed dir index key with index
   number 101 will fail with -EEXIST resulting in a transaction abort.

Fix this by locking the inode at btrfs_get_dir_last_index(), which is only
only used when opening a directory or attempting to lseek on it.

Reported-by: ken <[email protected]>
Link: https://lore.kernel.org/linux-btrfs/CAE6xmH+Lp=Q=E61bU+v9eWX8gYfLvu6jLYxjxjFpo3zHVPR0EQ@mail.gmail.com/
Reported-by: [email protected]
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Fixes: 9b378f6 ("btrfs: fix infinite directory reads")
CC: [email protected] # 6.5+
Signed-off-by: Filipe Manana <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
… tree"

This reverts commit 06f4543.

John Ogness reports the case that the allocation is in atomic context under
acquired spin-lock.

[   12.555784] BUG: sleeping function called from invalid context at include/linux/sched/mm.h:306
[   12.555808] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 70, name: kworker/1:2
[   12.555814] preempt_count: 1, expected: 0
[   12.555820] INFO: lockdep is turned off.
[   12.555824] irq event stamp: 208
[   12.555828] hardirqs last  enabled at (207): [<c00000000111e414>] ._raw_spin_unlock_irq+0x44/0x80
[   12.555850] hardirqs last disabled at (208): [<c00000000110ff94>] .__schedule+0x854/0xfe0
[   12.555859] softirqs last  enabled at (188): [<c000000000f73504>] .addrconf_verify_rtnl+0x2c4/0xb70
[   12.555872] softirqs last disabled at (182): [<c000000000f732b0>] .addrconf_verify_rtnl+0x70/0xb70
[   12.555884] CPU: 1 PID: 70 Comm: kworker/1:2 Tainted: G S                 6.6.0-rc1 #1
[   12.555893] Hardware name: PowerMac7,2 PPC970 0x390202 PowerMac
[   12.555898] Workqueue: firewire_ohci .bus_reset_work [firewire_ohci]
[   12.555939] Call Trace:
[   12.555944] [c000000009677830] [c0000000010d83c0] .dump_stack_lvl+0x8c/0xd0 (unreliable)
[   12.555963] [c0000000096778b0] [c000000000140270] .__might_resched+0x320/0x340
[   12.555978] [c000000009677940] [c000000000497600] .__kmem_cache_alloc_node+0x390/0x460
[   12.555993] [c000000009677a10] [c0000000003fe620] .__kmalloc+0x70/0x310
[   12.556007] [c000000009677ac0] [c0003d00004e2268] .fw_core_handle_bus_reset+0x2c8/0xba0 [firewire_core]
[   12.556060] [c000000009677c20] [c0003d0000491190] .bus_reset_work+0x330/0x9b0 [firewire_ohci]
[   12.556079] [c000000009677d10] [c00000000011d0d0] .process_one_work+0x280/0x6f0
[   12.556094] [c000000009677e10] [c00000000011d8a0] .worker_thread+0x360/0x500
[   12.556107] [c000000009677ef0] [c00000000012e3b4] .kthread+0x154/0x160
[   12.556120] [c000000009677f90] [c00000000000bfa8] .start_kernel_thread+0x10/0x14

Cc: [email protected]
Reported-by: John Ogness <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/raw
Signed-off-by: Takashi Sakamoto <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
When a PTP ethernet raw frame with a size of more than 256 bytes followed
by a 0xff pattern is sent to __skb_flow_dissect, nhoff value calculation
is wrong. For example: hdr->message_length takes the wrong value (0xffff)
and it does not replicate real header length. In this case, 'nhoff' value
was overridden and the PTP header was badly dissected. This leads to a
kernel crash.

net/core: flow_dissector
net/core flow dissector nhoff = 0x0000000e
net/core flow dissector hdr->message_length = 0x0000ffff
net/core flow dissector nhoff = 0x0001000d (u16 overflow)
...
skb linear:   00000000: 00 a0 c9 00 00 00 00 a0 c9 00 00 00 88
skb frag:     00000000: f7 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

Using the size of the ptp_header struct will allow the corrected
calculation of the nhoff value.

net/core flow dissector nhoff = 0x0000000e
net/core flow dissector nhoff = 0x00000030 (sizeof ptp_header)
...
skb linear:   00000000: 00 a0 c9 00 00 00 00 a0 c9 00 00 00 88 f7 ff ff
skb linear:   00000010: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
skb linear:   00000020: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
skb frag:     00000000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

Kernel trace:
[   74.984279] ------------[ cut here ]------------
[   74.989471] kernel BUG at include/linux/skbuff.h:2440!
[   74.995237] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[   75.001098] CPU: 4 PID: 0 Comm: swapper/4 Tainted: G     U            5.15.85-intel-ese-standard-lts #1
[   75.011629] Hardware name: Intel Corporation A-Island (CPU:AlderLake)/A-Island (ID:06), BIOS SB_ADLP.01.01.00.01.03.008.D-6A9D9E73-dirty Mar 30 2023
[   75.026507] RIP: 0010:eth_type_trans+0xd0/0x130
[   75.031594] Code: 03 88 47 78 eb c7 8b 47 68 2b 47 6c 48 8b 97 c0 00 00 00 83 f8 01 7e 1b 48 85 d2 74 06 66 83 3a ff 74 09 b8 00 04 00 00 eb ab <0f> 0b b8 00 01 00 00 eb a2 48 85 ff 74 eb 48 8d 54 24 06 31 f6 b9
[   75.052612] RSP: 0018:ffff9948c0228de0 EFLAGS: 00010297
[   75.058473] RAX: 00000000000003f2 RBX: ffff8e47047dc300 RCX: 0000000000001003
[   75.066462] RDX: ffff8e4e8c9ea040 RSI: ffff8e4704e0a000 RDI: ffff8e47047dc300
[   75.074458] RBP: ffff8e4704e2acc0 R08: 00000000000003f3 R09: 0000000000000800
[   75.082466] R10: 000000000000000d R11: ffff9948c0228dec R12: ffff8e4715e4e010
[   75.090461] R13: ffff9948c0545018 R14: 0000000000000001 R15: 0000000000000800
[   75.098464] FS:  0000000000000000(0000) GS:ffff8e4e8fb00000(0000) knlGS:0000000000000000
[   75.107530] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   75.113982] CR2: 00007f5eb35934a0 CR3: 0000000150e0a002 CR4: 0000000000770ee0
[   75.121980] PKRU: 55555554
[   75.125035] Call Trace:
[   75.127792]  <IRQ>
[   75.130063]  ? eth_get_headlen+0xa4/0xc0
[   75.134472]  igc_process_skb_fields+0xcd/0x150
[   75.139461]  igc_poll+0xc80/0x17b0
[   75.143272]  __napi_poll+0x27/0x170
[   75.147192]  net_rx_action+0x234/0x280
[   75.151409]  __do_softirq+0xef/0x2f4
[   75.155424]  irq_exit_rcu+0xc7/0x110
[   75.159432]  common_interrupt+0xb8/0xd0
[   75.163748]  </IRQ>
[   75.166112]  <TASK>
[   75.168473]  asm_common_interrupt+0x22/0x40
[   75.173175] RIP: 0010:cpuidle_enter_state+0xe2/0x350
[   75.178749] Code: 85 c0 0f 8f 04 02 00 00 31 ff e8 39 6c 67 ff 45 84 ff 74 12 9c 58 f6 c4 02 0f 85 50 02 00 00 31 ff e8 52 b0 6d ff fb 45 85 f6 <0f> 88 b1 00 00 00 49 63 ce 4c 2b 2c 24 48 89 c8 48 6b d1 68 48 c1
[   75.199757] RSP: 0018:ffff9948c013bea8 EFLAGS: 00000202
[   75.205614] RAX: ffff8e4e8fb00000 RBX: ffffb948bfd23900 RCX: 000000000000001f
[   75.213619] RDX: 0000000000000004 RSI: ffffffff94206161 RDI: ffffffff94212e20
[   75.221620] RBP: 0000000000000004 R08: 000000117568973a R09: 0000000000000001
[   75.229622] R10: 000000000000afc8 R11: ffff8e4e8fb29ce4 R12: ffffffff945ae980
[   75.237628] R13: 000000117568973a R14: 0000000000000004 R15: 0000000000000000
[   75.245635]  ? cpuidle_enter_state+0xc7/0x350
[   75.250518]  cpuidle_enter+0x29/0x40
[   75.254539]  do_idle+0x1d9/0x260
[   75.258166]  cpu_startup_entry+0x19/0x20
[   75.262582]  secondary_startup_64_no_verify+0xc2/0xcb
[   75.268259]  </TASK>
[   75.270721] Modules linked in: 8021q snd_sof_pci_intel_tgl snd_sof_intel_hda_common tpm_crb snd_soc_hdac_hda snd_sof_intel_hda snd_hda_ext_core snd_sof_pci snd_sof snd_sof_xtensa_dsp snd_soc_acpi_intel_match snd_soc_acpi snd_soc_core snd_compress iTCO_wdt ac97_bus intel_pmc_bxt mei_hdcp iTCO_vendor_support snd_hda_codec_hdmi pmt_telemetry intel_pmc_core pmt_class snd_hda_intel x86_pkg_temp_thermal snd_intel_dspcfg snd_hda_codec snd_hda_core kvm_intel snd_pcm snd_timer kvm snd mei_me soundcore tpm_tis irqbypass i2c_i801 mei tpm_tis_core pcspkr intel_rapl_msr tpm i2c_smbus intel_pmt thermal sch_fq_codel uio uhid i915 drm_buddy video drm_display_helper drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm fuse configfs
[   75.342736] ---[ end trace 3785f9f360400e3a ]---
[   75.347913] RIP: 0010:eth_type_trans+0xd0/0x130
[   75.352984] Code: 03 88 47 78 eb c7 8b 47 68 2b 47 6c 48 8b 97 c0 00 00 00 83 f8 01 7e 1b 48 85 d2 74 06 66 83 3a ff 74 09 b8 00 04 00 00 eb ab <0f> 0b b8 00 01 00 00 eb a2 48 85 ff 74 eb 48 8d 54 24 06 31 f6 b9
[   75.373994] RSP: 0018:ffff9948c0228de0 EFLAGS: 00010297
[   75.379860] RAX: 00000000000003f2 RBX: ffff8e47047dc300 RCX: 0000000000001003
[   75.387856] RDX: ffff8e4e8c9ea040 RSI: ffff8e4704e0a000 RDI: ffff8e47047dc300
[   75.395864] RBP: ffff8e4704e2acc0 R08: 00000000000003f3 R09: 0000000000000800
[   75.403857] R10: 000000000000000d R11: ffff9948c0228dec R12: ffff8e4715e4e010
[   75.411863] R13: ffff9948c0545018 R14: 0000000000000001 R15: 0000000000000800
[   75.419875] FS:  0000000000000000(0000) GS:ffff8e4e8fb00000(0000) knlGS:0000000000000000
[   75.428946] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   75.435403] CR2: 00007f5eb35934a0 CR3: 0000000150e0a002 CR4: 0000000000770ee0
[   75.443410] PKRU: 55555554
[   75.446477] Kernel panic - not syncing: Fatal exception in interrupt
[   75.453738] Kernel Offset: 0x11c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[   75.465794] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

Fixes: 4f1cc51 ("net: flow_dissector: Parse PTP L2 packet header")
Signed-off-by: Sasha Neftin <[email protected]>
Reviewed-by: Jiri Pirko <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
Fix an error detected by memory sanitizer:
```
==4033==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x55fb0fbedfc7 in read_alias_info tools/perf/util/pmu.c:457:6
    #1 0x55fb0fbea339 in check_info_data tools/perf/util/pmu.c:1434:2
    Rust-for-Linux#2 0x55fb0fbea339 in perf_pmu__check_alias tools/perf/util/pmu.c:1504:9
    Rust-for-Linux#3 0x55fb0fbdca85 in parse_events_add_pmu tools/perf/util/parse-events.c:1429:32
    Rust-for-Linux#4 0x55fb0f965230 in parse_events_parse tools/perf/util/parse-events.y:299:6
    Rust-for-Linux#5 0x55fb0fbdf6b2 in parse_events__scanner tools/perf/util/parse-events.c:1822:8
    Rust-for-Linux#6 0x55fb0fbdf8c1 in __parse_events tools/perf/util/parse-events.c:2094:8
    Rust-for-Linux#7 0x55fb0fa8ffa9 in parse_events tools/perf/util/parse-events.h:41:9
    Rust-for-Linux#8 0x55fb0fa8ffa9 in test_event tools/perf/tests/parse-events.c:2393:8
    Rust-for-Linux#9 0x55fb0fa8f458 in test__pmu_events tools/perf/tests/parse-events.c:2551:15
    Rust-for-Linux#10 0x55fb0fa6d93f in run_test tools/perf/tests/builtin-test.c:242:9
    Rust-for-Linux#11 0x55fb0fa6d93f in test_and_print tools/perf/tests/builtin-test.c:271:8
    Rust-for-Linux#12 0x55fb0fa6d082 in __cmd_test tools/perf/tests/builtin-test.c:442:5
    Rust-for-Linux#13 0x55fb0fa6d082 in cmd_test tools/perf/tests/builtin-test.c:564:9
    Rust-for-Linux#14 0x55fb0f942720 in run_builtin tools/perf/perf.c:322:11
    Rust-for-Linux#15 0x55fb0f942486 in handle_internal_command tools/perf/perf.c:375:8
    Rust-for-Linux#16 0x55fb0f941dab in run_argv tools/perf/perf.c:419:2
    Rust-for-Linux#17 0x55fb0f941dab in main tools/perf/perf.c:535:3
```

Fixes: 7b723db ("perf pmu: Be lazy about loading event info files from sysfs")
Signed-off-by: Ian Rogers <[email protected]>
Cc: James Clark <[email protected]>
Cc: Kan Liang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
Breno and Josef report a deadlock scenario from cgroup reclaim
re-entering the filesystem:

[  361.546690] ======================================================
[  361.559210] WARNING: possible circular locking dependency detected
[  361.571703] 6.5.0-0_fbk700_debug_rc0_kbuilder_13159_gbf787a128001 #1 Tainted: G S          E
[  361.589704] ------------------------------------------------------
[  361.602277] find/9315 is trying to acquire lock:
[  361.611625] ffff88837ba140c0 (&delayed_node->mutex){+.+.}-{4:4}, at: __btrfs_release_delayed_node+0x68/0x4f0
[  361.631437]
[  361.631437] but task is already holding lock:
[  361.643243] ffff8881765b8678 (btrfs-tree-01){++++}-{4:4}, at: btrfs_tree_read_lock+0x1e/0x40

[  362.904457]  mutex_lock_nested+0x1c/0x30
[  362.912414]  __btrfs_release_delayed_node+0x68/0x4f0
[  362.922460]  btrfs_evict_inode+0x301/0x770
[  362.982726]  evict+0x17c/0x380
[  362.988944]  prune_icache_sb+0x100/0x1d0
[  363.005559]  super_cache_scan+0x1f8/0x260
[  363.013695]  do_shrink_slab+0x2a2/0x540
[  363.021489]  shrink_slab_memcg+0x237/0x3d0
[  363.050606]  shrink_slab+0xa7/0x240
[  363.083382]  shrink_node_memcgs+0x262/0x3b0
[  363.091870]  shrink_node+0x1a4/0x720
[  363.099150]  shrink_zones+0x1f6/0x5d0
[  363.148798]  do_try_to_free_pages+0x19b/0x5e0
[  363.157633]  try_to_free_mem_cgroup_pages+0x266/0x370
[  363.190575]  reclaim_high+0x16f/0x1f0
[  363.208409]  mem_cgroup_handle_over_high+0x10b/0x270
[  363.246678]  try_charge_memcg+0xaf2/0xc70
[  363.304151]  charge_memcg+0xf0/0x350
[  363.320070]  __mem_cgroup_charge+0x28/0x40
[  363.328371]  __filemap_add_folio+0x870/0xd50
[  363.371303]  filemap_add_folio+0xdd/0x310
[  363.399696]  __filemap_get_folio+0x2fc/0x7d0
[  363.419086]  pagecache_get_page+0xe/0x30
[  363.427048]  alloc_extent_buffer+0x1cd/0x6a0
[  363.435704]  read_tree_block+0x43/0xc0
[  363.443316]  read_block_for_search+0x361/0x510
[  363.466690]  btrfs_search_slot+0xc8c/0x1520

This is caused by the mem_cgroup_handle_over_high() not respecting the
gfp_mask of the allocation context.  We used to only call this function on
resume to userspace, where no locks were held.  But c9afe31 ("memcg:
synchronously enforce memory.high for large overcharges") added a call
from the allocation context without considering the gfp.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: c9afe31 ("memcg: synchronously enforce memory.high for large overcharges")
Signed-off-by: Johannes Weiner <[email protected]>
Reported-by: Breno Leitao <[email protected]>
Reported-by: Josef Bacik <[email protected]>
Acked-by: Shakeel Butt <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: <[email protected]>	[5.17+]
Signed-off-by: Andrew Morton <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
After commit 61167ad ("mm: pass nid to reserve_bootmem_region()")
we get a panic if DEFERRED_STRUCT_PAGE_INIT is enabled:

[    0.000000] CPU 0 Unable to handle kernel paging request at virtual address 0000000000002b82, era == 90000000040e3f28, ra == 90000000040e3f18
[    0.000000] Oops[#1]:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0+ Rust-for-Linux#733
[    0.000000] pc 90000000040e3f28 ra 90000000040e3f18 tp 90000000046f4000 sp 90000000046f7c90
[    0.000000] a0 0000000000000001 a1 0000000000200000 a2 0000000000000040 a3 90000000046f7ca0
[    0.000000] a4 90000000046f7ca4 a5 0000000000000000 a6 90000000046f7c38 a7 0000000000000000
[    0.000000] t0 0000000000000002 t1 9000000004b00ac8 t2 90000000040e3f18 t3 90000000040f0800
[    0.000000] t4 00000000000f0000 t5 80000000ffffe07e t6 0000000000000003 t7 900000047fff5e20
[    0.000000] t8 aaaaaaaaaaaaaaab u0 0000000000000018 s9 0000000000000000 s0 fffffefffe000000
[    0.000000] s1 0000000000000000 s2 0000000000000080 s3 0000000000000040 s4 0000000000000000
[    0.000000] s5 0000000000000000 s6 fffffefffe000000 s7 900000000470b740 s8 9000000004ad4000
[    0.000000]    ra: 90000000040e3f18 reserve_bootmem_region+0xec/0x21c
[    0.000000]   ERA: 90000000040e3f28 reserve_bootmem_region+0xfc/0x21c
[    0.000000]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
[    0.000000]  PRMD: 00000000 (PPLV0 -PIE -PWE)
[    0.000000]  EUEN: 00000000 (-FPE -SXE -ASXE -BTE)
[    0.000000]  ECFG: 0007080 (LIE=11 VS=7)
[    0.000000] ESTAT: 00010800 [PIL] (IS=11 ECode=1 EsubCode=0)
[    0.000000]  BADV: 0000000000002b82
[    0.000000]  PRID: 0014d000 (Loongson-64bit, Loongson-3A6000)
[    0.000000] Modules linked in:
[    0.000000] Process swapper (pid: 0, threadinfo=(____ptrval____), task=(____ptrval____))
[    0.000000] Stack : 0000000000000000 9000000002eb5430 0000003a00000020 90000000045ccd00
[    0.000000]         900000000470e000 90000000002c1918 0000000000000000 9000000004110780
[    0.000000]         00000000fe6c0000 0000000480000000 9000000004b4e368 9000000004110748
[    0.000000]         0000000000000000 900000000421ca84 9000000004620000 9000000004564970
[    0.000000]         90000000046f7d78 9000000002cc9f70 90000000002c1918 900000000470e000
[    0.000000]         9000000004564970 90000000040bc0e0 90000000046f7d78 0000000000000000
[    0.000000]         0000000000004000 90000000045ccd00 0000000000000000 90000000002c1918
[    0.000000]         90000000002c1900 900000000470b700 9000000004b4df78 9000000004620000
[    0.000000]         90000000046200a8 90000000046200a8 0000000000000000 9000000004218b2c
[    0.000000]         9000000004270008 0000000000000001 0000000000000000 90000000045ccd00
[    0.000000]         ...
[    0.000000] Call Trace:
[    0.000000] [<90000000040e3f28>] reserve_bootmem_region+0xfc/0x21c
[    0.000000] [<900000000421ca84>] memblock_free_all+0x114/0x350
[    0.000000] [<9000000004218b2c>] mm_core_init+0x138/0x3cc
[    0.000000] [<9000000004200e38>] start_kernel+0x488/0x7a4
[    0.000000] [<90000000040df0d8>] kernel_entry+0xd8/0xdc
[    0.000000]
[    0.000000] Code: 02eb21ad  00410f4c  380c31a <262b818d> 6800b70d  02c1c196  0015001c  57fe4bb1  260002cd

The reason is early memblock_reserve() in memblock_init() set node id to
MAX_NUMNODES, making NODE_DATA(nid) a NULL dereference in the call chain
reserve_bootmem_region() -> init_reserved_page(). After memblock_init(),
those late calls of memblock_reserve() operate on subregions of memblock
.memory regions. As a result, these reserved regions will be set to the
correct node at the first iteration of memmap_init_reserved_pages().

So set all reserved memblocks on Node#0 at initialization can avoid this
panic.

Reported-by: WANG Xuerui <[email protected]>
Tested-by: WANG Xuerui <[email protected]>
Reviewed-by: WANG Xuerui <[email protected]>  # with nits addressed
Signed-off-by: Huacai Chen <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
…alid

If smb2 request from client is invalid, The following kernel oops could
happen. The patch e2b76ab: "ksmbd: add support for read compound"
leads this issue. When request is invalid, It doesn't set anything in
the response buffer. This patch add missing set invalid parameter error
response.

[  673.085542] ksmbd: cli req too short, len 184 not 142. cmd:5 mid:109
[  673.085580] BUG: kernel NULL pointer dereference, address: 0000000000000000
[  673.085591] #PF: supervisor read access in kernel mode
[  673.085600] #PF: error_code(0x0000) - not-present page
[  673.085608] PGD 0 P4D 0
[  673.085620] Oops: 0000 [#1] PREEMPT SMP NOPTI
[  673.085631] CPU: 3 PID: 1039 Comm: kworker/3:0 Not tainted 6.6.0-rc2-tmt Rust-for-Linux#16
[  673.085643] Hardware name: AZW U59/U59, BIOS JTKT001 05/05/2022
[  673.085651] Workqueue: ksmbd-io handle_ksmbd_work [ksmbd]
[  673.085719] RIP: 0010:ksmbd_conn_write+0x68/0xc0 [ksmbd]
[  673.085808] RAX: 0000000000000000 RBX: ffff88811ade4f00 RCX: 0000000000000000
[  673.085817] RDX: 0000000000000000 RSI: ffff88810c2a9780 RDI: ffff88810c2a9ac0
[  673.085826] RBP: ffffc900005e3e00 R08: 0000000000000000 R09: 0000000000000000
[  673.085834] R10: ffffffffa3168160 R11: 63203a64626d736b R12: ffff8881057c8800
[  673.085842] R13: ffff8881057c8820 R14: ffff8882781b2380 R15: ffff8881057c8800
[  673.085852] FS:  0000000000000000(0000) GS:ffff888278180000(0000) knlGS:0000000000000000
[  673.085864] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  673.085872] CR2: 0000000000000000 CR3: 000000015b63c000 CR4: 0000000000350ee0
[  673.085883] Call Trace:
[  673.085890]  <TASK>
[  673.085900]  ? show_regs+0x6a/0x80
[  673.085916]  ? __die+0x25/0x70
[  673.085926]  ? page_fault_oops+0x154/0x4b0
[  673.085938]  ? tick_nohz_tick_stopped+0x18/0x50
[  673.085954]  ? __irq_work_queue_local+0xba/0x140
[  673.085967]  ? do_user_addr_fault+0x30f/0x6c0
[  673.085979]  ? exc_page_fault+0x79/0x180
[  673.085992]  ? asm_exc_page_fault+0x27/0x30
[  673.086009]  ? ksmbd_conn_write+0x68/0xc0 [ksmbd]
[  673.086067]  ? ksmbd_conn_write+0x46/0xc0 [ksmbd]
[  673.086123]  handle_ksmbd_work+0x28d/0x4b0 [ksmbd]
[  673.086177]  process_one_work+0x178/0x350
[  673.086193]  ? __pfx_worker_thread+0x10/0x10
[  673.086202]  worker_thread+0x2f3/0x420
[  673.086210]  ? _raw_spin_unlock_irqrestore+0x27/0x50
[  673.086222]  ? __pfx_worker_thread+0x10/0x10
[  673.086230]  kthread+0x103/0x140
[  673.086242]  ? __pfx_kthread+0x10/0x10
[  673.086253]  ret_from_fork+0x39/0x60
[  673.086263]  ? __pfx_kthread+0x10/0x10
[  673.086274]  ret_from_fork_asm+0x1b/0x30

Fixes: e2b76ab ("ksmbd: add support for read compound")
Reported-by: Tom Talpey <[email protected]>
Signed-off-by: Namjae Jeon <[email protected]>
Signed-off-by: Steve French <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
Inject fault while probing mdpy.ko, if kstrdup() of create_dir() fails in
kobject_add_internal() in kobject_init_and_add() in mdev_type_add()
in parent_create_sysfs_files(), it will return 0 and probe successfully.
And when rmmod mdpy.ko, the mdpy_dev_exit() will call
mdev_unregister_parent(), the mdev_type_remove() may traverse uninitialized
parent->types[i] in parent_remove_sysfs_files(), and it will cause
below null-ptr-deref.

If mdev_type_add() fails, return the error code and kset_unregister()
to fix the issue.

 general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
 KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
 CPU: 2 PID: 10215 Comm: rmmod Tainted: G        W        N 6.6.0-rc2+ Rust-for-Linux#20
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
 RIP: 0010:__kobject_del+0x62/0x1c0
 Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 51 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 28 48 8d 7d 10 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 24 01 00 00 48 8b 75 10 48 89 df 48 8d 6b 3c e8
 RSP: 0018:ffff88810695fd30 EFLAGS: 00010202
 RAX: dffffc0000000000 RBX: ffffffffa0270268 RCX: 0000000000000000
 RDX: 0000000000000002 RSI: 0000000000000004 RDI: 0000000000000010
 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10233a4ef1
 R10: ffff888119d2778b R11: 0000000063666572 R12: 0000000000000000
 R13: fffffbfff404e2d4 R14: dffffc0000000000 R15: ffffffffa0271660
 FS:  00007fbc81981540(0000) GS:ffff888119d00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007fc14a142dc0 CR3: 0000000110a62003 CR4: 0000000000770ee0
 DR0: ffffffff8fb0bce8 DR1: ffffffff8fb0bce9 DR2: ffffffff8fb0bcea
 DR3: ffffffff8fb0bceb DR6: 00000000fffe0ff0 DR7: 0000000000000600
 PKRU: 55555554
 Call Trace:
  <TASK>
  ? die_addr+0x3d/0xa0
  ? exc_general_protection+0x144/0x220
  ? asm_exc_general_protection+0x22/0x30
  ? __kobject_del+0x62/0x1c0
  kobject_del+0x32/0x50
  parent_remove_sysfs_files+0xd6/0x170 [mdev]
  mdev_unregister_parent+0xfb/0x190 [mdev]
  ? mdev_register_parent+0x270/0x270 [mdev]
  ? find_module_all+0x9d/0xe0
  mdpy_dev_exit+0x17/0x63 [mdpy]
  __do_sys_delete_module.constprop.0+0x2fa/0x4b0
  ? module_flags+0x300/0x300
  ? __fput+0x4e7/0xa00
  do_syscall_64+0x35/0x80
  entry_SYSCALL_64_after_hwframe+0x46/0xb0
 RIP: 0033:0x7fbc813221b7
 Code: 73 01 c3 48 8b 0d d1 8c 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 8c 2c 00 f7 d8 64 89 01 48
 RSP: 002b:00007ffe780e0648 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
 RAX: ffffffffffffffda RBX: 00007ffe780e06a8 RCX: 00007fbc813221b7
 RDX: 000000000000000a RSI: 0000000000000800 RDI: 000055e214df9b58
 RBP: 000055e214df9af0 R08: 00007ffe780df5c1 R09: 0000000000000000
 R10: 00007fbc8139ecc0 R11: 0000000000000206 R12: 00007ffe780e0870
 R13: 00007ffe780e0ed0 R14: 000055e214df9260 R15: 000055e214df9af0
  </TASK>
 Modules linked in: mdpy(-) mdev vfio_iommu_type1 vfio [last unloaded: mdpy]
 Dumping ftrace buffer:
    (ftrace buffer empty)
 ---[ end trace 0000000000000000 ]---
 RIP: 0010:__kobject_del+0x62/0x1c0
 Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 51 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 28 48 8d 7d 10 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 24 01 00 00 48 8b 75 10 48 89 df 48 8d 6b 3c e8
 RSP: 0018:ffff88810695fd30 EFLAGS: 00010202
 RAX: dffffc0000000000 RBX: ffffffffa0270268 RCX: 0000000000000000
 RDX: 0000000000000002 RSI: 0000000000000004 RDI: 0000000000000010
 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10233a4ef1
 R10: ffff888119d2778b R11: 0000000063666572 R12: 0000000000000000
 R13: fffffbfff404e2d4 R14: dffffc0000000000 R15: ffffffffa0271660
 FS:  00007fbc81981540(0000) GS:ffff888119d00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007fc14a142dc0 CR3: 0000000110a62003 CR4: 0000000000770ee0
 DR0: ffffffff8fb0bce8 DR1: ffffffff8fb0bce9 DR2: ffffffff8fb0bcea
 DR3: ffffffff8fb0bceb DR6: 00000000fffe0ff0 DR7: 0000000000000600
 PKRU: 55555554
 Kernel panic - not syncing: Fatal exception
 Dumping ftrace buffer:
    (ftrace buffer empty)
 Kernel Offset: disabled
 Rebooting in 1 seconds..

Fixes: da44c34 ("vfio/mdev: simplify mdev_type handling")
Signed-off-by: Jinjie Ruan <[email protected]>
Reviewed-by: Eric Farman <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alex Williamson <[email protected]>
y86-dev pushed a commit that referenced this pull request Oct 9, 2023
… into HEAD

KVM/riscv fixes for 6.6, take #1

- Fix KVM_GET_REG_LIST API for ISA_EXT registers
- Fix reading ISA_EXT register of a missing extension
- Fix ISA_EXT register handling in get-reg-list test
- Fix filtering of AIA registers in get-reg-list test
y86-dev pushed a commit that referenced this pull request Dec 13, 2023
The commit 5721d4e enhanced dm-verity, so that it can verify blocks
from tasklets rather than from workqueues. This reportedly improves
performance significantly.

However, dm-verity was using the flag CRYPTO_TFM_REQ_MAY_SLEEP from
tasklets which resulted in warnings about sleeping function being called
from non-sleeping context.

BUG: sleeping function called from invalid context at crypto/internal.h:206
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 14, name: ksoftirqd/0
preempt_count: 100, expected: 0
RCU nest depth: 0, expected: 0
CPU: 0 PID: 14 Comm: ksoftirqd/0 Tainted: G        W 6.7.0-rc1 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x32/0x50
 __might_resched+0x110/0x160
 crypto_hash_walk_done+0x54/0xb0
 shash_ahash_update+0x51/0x60
 verity_hash_update.isra.0+0x4a/0x130 [dm_verity]
 verity_verify_io+0x165/0x550 [dm_verity]
 ? free_unref_page+0xdf/0x170
 ? psi_group_change+0x113/0x390
 verity_tasklet+0xd/0x70 [dm_verity]
 tasklet_action_common.isra.0+0xb3/0xc0
 __do_softirq+0xaf/0x1ec
 ? smpboot_thread_fn+0x1d/0x200
 ? sort_range+0x20/0x20
 run_ksoftirqd+0x15/0x30
 smpboot_thread_fn+0xed/0x200
 kthread+0xdc/0x110
 ? kthread_complete_and_exit+0x20/0x20
 ret_from_fork+0x28/0x40
 ? kthread_complete_and_exit+0x20/0x20
 ret_from_fork_asm+0x11/0x20
 </TASK>

This commit fixes dm-verity so that it doesn't use the flags
CRYPTO_TFM_REQ_MAY_SLEEP and CRYPTO_TFM_REQ_MAY_BACKLOG from tasklets. The
crypto API would do GFP_ATOMIC allocation instead, it could return -ENOMEM
and we catch -ENOMEM in verity_tasklet and requeue the request to the
workqueue.

Signed-off-by: Mikulas Patocka <[email protected]>
Cc: [email protected]	# v6.0+
Fixes: 5721d4e ("dm verity: Add optional "try_verify_in_tasklet" feature")
Signed-off-by: Mike Snitzer <[email protected]>
y86-dev pushed a commit that referenced this pull request Dec 13, 2023
We get a kernel crash about "unable to handle kernel paging request":

```dmesg
[368033.032005] BUG: unable to handle kernel paging request at ffffffffad9ae4b5
[368033.032007] PGD fc3a0d067 P4D fc3a0d067 PUD fc3a0e063 PMD 8000000fc38000e1
[368033.032012] Oops: 0003 [#1] SMP PTI
[368033.032015] CPU: 23 PID: 55090 Comm: bch_dirtcnt[0] Kdump: loaded Tainted: G           OE    --------- -  - 4.18.0-147.5.1.es8_24.x86_64 #1
[368033.032017] Hardware name: Tsinghua Tongfang THTF Chaoqiang Server/072T6D, BIOS 2.4.3 01/17/2017
[368033.032027] RIP: 0010:native_queued_spin_lock_slowpath+0x183/0x1d0
[368033.032029] Code: 8b 02 48 85 c0 74 f6 48 89 c1 eb d0 c1 e9 12 83 e0
03 83 e9 01 48 c1 e0 05 48 63 c9 48 05 c0 3d 02 00 48 03 04 cd 60 68 93
ad <48> 89 10 8b 42 08 85 c0 75 09 f3 90 8b 42 08 85 c0 74 f7 48 8b 02
[368033.032031] RSP: 0018:ffffbb48852abe00 EFLAGS: 00010082
[368033.032032] RAX: ffffffffad9ae4b5 RBX: 0000000000000246 RCX: 0000000000003bf3
[368033.032033] RDX: ffff97b0ff8e3dc0 RSI: 0000000000600000 RDI: ffffbb4884743c68
[368033.032034] RBP: 0000000000000001 R08: 0000000000000000 R09: 000007ffffffffff
[368033.032035] R10: ffffbb486bb01000 R11: 0000000000000001 R12: ffffffffc068da70
[368033.032036] R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000000
[368033.032038] FS:  0000000000000000(0000) GS:ffff97b0ff8c0000(0000) knlGS:0000000000000000
[368033.032039] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[368033.032040] CR2: ffffffffad9ae4b5 CR3: 0000000fc3a0a002 CR4: 00000000003626e0
[368033.032042] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[368033.032043] bcache: bch_cached_dev_attach() Caching rbd479 as bcache462 on set 8cff3c36-4a76-4242-afaa-7630206bc70b
[368033.032045] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[368033.032046] Call Trace:
[368033.032054]  _raw_spin_lock_irqsave+0x32/0x40
[368033.032061]  __wake_up_common_lock+0x63/0xc0
[368033.032073]  ? bch_ptr_invalid+0x10/0x10 [bcache]
[368033.033502]  bch_dirty_init_thread+0x14c/0x160 [bcache]
[368033.033511]  ? read_dirty_submit+0x60/0x60 [bcache]
[368033.033516]  kthread+0x112/0x130
[368033.033520]  ? kthread_flush_work_fn+0x10/0x10
[368033.034505]  ret_from_fork+0x35/0x40
```

The crash occurred when call wake_up(&state->wait), and then we want
to look at the value in the state. However, bch_sectors_dirty_init()
is not found in the stack of any task. Since state is allocated on
the stack, we guess that bch_sectors_dirty_init() has exited, causing
bch_dirty_init_thread() to be unable to handle kernel paging request.

In order to verify this idea, we added some printing information during
wake_up(&state->wait). We find that "wake up" is printed twice, however
we only expect the last thread to wake up once.

```dmesg
[  994.641004] alcache: bch_dirty_init_thread() wake up
[  994.641018] alcache: bch_dirty_init_thread() wake up
[  994.641523] alcache: bch_sectors_dirty_init() init exit
```

There is a race. If bch_sectors_dirty_init() exits after the first wake
up, the second wake up will trigger this bug("unable to handle kernel
paging request").

Proceed as follows:

bch_sectors_dirty_init
    kthread_run ==============> bch_dirty_init_thread(bch_dirtcnt[0])
            ...                         ...
    atomic_inc(&state.started)          ...
            ...                         ...
    atomic_read(&state.enough)          ...
            ...                 atomic_set(&state->enough, 1)
    kthread_run ======================================================> bch_dirty_init_thread(bch_dirtcnt[1])
            ...                 atomic_dec_and_test(&state->started)            ...
    atomic_inc(&state.started)          ...                                     ...
            ...                 wake_up(&state->wait)                           ...
    atomic_read(&state.enough)                                          atomic_dec_and_test(&state->started)
            ...                                                                 ...
    wait_event(state.wait, atomic_read(&state.started) == 0)                    ...
    return                                                                      ...
                                                                        wake_up(&state->wait)

We believe it is very common to wake up twice if there is no dirty, but
crash is an extremely low probability event. It's hard for us to reproduce
this issue. We attached and detached continuously for a week, with a total
of more than one million attaches and only one crash.

Putting atomic_inc(&state.started) before kthread_run() can avoid waking
up twice.

Fixes: b144e45 ("bcache: make bch_sectors_dirty_init() to be multithreaded")
Signed-off-by: Mingzhe Zou <[email protected]>
Cc:  <[email protected]>
Signed-off-by: Coly Li <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
y86-dev pushed a commit that referenced this pull request Dec 13, 2023
…f-times'

Eduard Zingerman says:

====================
verify callbacks as if they are called unknown number of times

This series updates verifier logic for callback functions handling.
Current master simulates callback body execution exactly once,
which leads to verifier not detecting unsafe programs like below:

    static int unsafe_on_zero_iter_cb(__u32 idx, struct num_context *ctx)
    {
        ctx->i = 0;
        return 0;
    }

    SEC("?raw_tp")
    int unsafe_on_zero_iter(void *unused)
    {
        struct num_context loop_ctx = { .i = 32 };
        __u8 choice_arr[2] = { 0, 1 };

        bpf_loop(100, unsafe_on_zero_iter_cb, &loop_ctx, 0);
        return choice_arr[loop_ctx.i];
    }

This was reported previously in [0].
The basic idea of the fix is to schedule callback entry state for
verification in env->head until some identical, previously visited
state in current DFS state traversal is found. Same logic as with open
coded iterators, and builds on top recent fixes [1] for those.

The series is structured as follows:
- patches #1,2,3 update strobemeta, xdp_synproxy selftests and
  bpf_loop_bench benchmark to allow convergence of the bpf_loop
  callback states;
- patches Rust-for-Linux#4,5 just shuffle the code a bit;
- patch Rust-for-Linux#6 is the main part of the series;
- patch Rust-for-Linux#7 adds test cases for Rust-for-Linux#6;
- patch Rust-for-Linux#8 extend patch Rust-for-Linux#6 with same speculative scalar widening
  logic, as used for open coded iterators;
- patch Rust-for-Linux#9 adds test cases for Rust-for-Linux#8;
- patch Rust-for-Linux#10 extends patch Rust-for-Linux#6 to track maximal number of callback
  executions specifically for bpf_loop();
- patch Rust-for-Linux#11 adds test cases for Rust-for-Linux#10.

Veristat results comparing this series to master+patches #1,2,3 using selftests
show the following difference:

File                       Program        States (A)  States (B)  States (DIFF)
-------------------------  -------------  ----------  ----------  -------------
bpf_loop_bench.bpf.o       benchmark               1           2  +1 (+100.00%)
pyperf600_bpf_loop.bpf.o   on_event              322         407  +85 (+26.40%)
strobemeta_bpf_loop.bpf.o  on_event              113         151  +38 (+33.63%)
xdp_synproxy_kern.bpf.o    syncookie_tc          341         291  -50 (-14.66%)
xdp_synproxy_kern.bpf.o    syncookie_xdp         344         301  -43 (-12.50%)

Veristat results comparing this series to master using Tetragon BPF
files [2] also show some differences.
States diff varies from +2% to +15% on 23 programs out of 186,
no new failures.

Changelog:
- V3 [5] -> V4, changes suggested by Andrii:
  - validate mark_chain_precision() result in patch Rust-for-Linux#10;
  - renaming s/cumulative_callback_depth/callback_unroll_depth/.
- V2 [4] -> V3:
  - fixes in expected log messages for test cases:
    - callback_result_precise;
    - parent_callee_saved_reg_precise_with_callback;
    - parent_stack_slot_precise_with_callback;
  - renamings (suggested by Alexei):
    - s/callback_iter_depth/cumulative_callback_depth/
    - s/is_callback_iter_next/calls_callback/
    - s/mark_callback_iter_next/mark_calls_callback/
  - prepare_func_exit() updated to exit with -EFAULT when
    callee->in_callback_fn is true but calls_callback() is not true
    for callsite;
  - test case 'bpf_loop_iter_limit_nested' rewritten to use return
    value check instead of verifier log message checks
    (suggested by Alexei).
- V1 [3] -> V2, changes suggested by Andrii:
  - small changes for error handling code in __check_func_call();
  - callback body processing log is now matched in relevant
    verifier_subprog_precision.c tests;
  - R1 passed to bpf_loop() is now always marked as precise;
  - log level 2 message for bpf_loop() iteration termination instead of
    iteration depth messages;
  - __no_msg macro removed;
  - bpf_loop_iter_limit_nested updated to avoid using __no_msg;
  - commit message for patch Rust-for-Linux#3 updated according to Alexei's request.

[0] https://lore.kernel.org/bpf/CA+vRuzPChFNXmouzGG+wsy=6eMcfr1mFG0F3g7rbg-sedGKW3w@mail.gmail.com/
[1] https://lore.kernel.org/bpf/[email protected]/
[2] [email protected]:cilium/tetragon.git
[3] https://lore.kernel.org/bpf/[email protected]/T/#t
[4] https://lore.kernel.org/bpf/[email protected]/T/#t
[5] https://lore.kernel.org/bpf/[email protected]/T/#t
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
y86-dev pushed a commit that referenced this pull request Apr 21, 2025
The following crash is observed while handling an IOMMU fault with a
recent kernel:

kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
BUG: unable to handle page fault for address: ffff8c708299f700
PGD 19ee01067 P4D 19ee01067 PUD 101c10063 PMD 80000001028001e3
Oops: Oops: 0011 [#1] SMP NOPTI
CPU: 4 UID: 0 PID: 139 Comm: irq/25-AMD-Vi Not tainted 6.15.0-rc1+ Rust-for-Linux#20 PREEMPT(lazy)
Hardware name: LENOVO 21D0/LNVNB161216, BIOS J6CN50WW 09/27/2024
RIP: 0010:0xffff8c708299f700
Call Trace:
 <TASK>
 ? report_iommu_fault+0x78/0xd3
 ? amd_iommu_report_page_fault+0x91/0x150
 ? amd_iommu_int_thread+0x77/0x180
 ? __pfx_irq_thread_fn+0x10/0x10
 ? irq_thread_fn+0x23/0x60
 ? irq_thread+0xf9/0x1e0
 ? __pfx_irq_thread_dtor+0x10/0x10
 ? __pfx_irq_thread+0x10/0x10
 ? kthread+0xfc/0x240
 ? __pfx_kthread+0x10/0x10
 ? ret_from_fork+0x34/0x50
 ? __pfx_kthread+0x10/0x10
 ? ret_from_fork_asm+0x1a/0x30
 </TASK>

report_iommu_fault() checks for an installed handler comparing the
corresponding field to NULL. It can (and could before) be called for a
domain with a different cookie type - IOMMU_COOKIE_DMA_IOVA, specifically.
Cookie is represented as a union so we may end up with a garbage value
treated there if this happens for a domain with another cookie type.

Formerly there were two exclusive cookie types in the union.
IOMMU_DOMAIN_SVA has a dedicated iommu_report_device_fault().

Call the fault handler only if the passed domain has a required cookie
type.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 6aa63a4 ("iommu: Sort out domain user data")
Signed-off-by: Fedor Pchelkin <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Joerg Roedel <[email protected]>
y86-dev pushed a commit that referenced this pull request Apr 21, 2025
When testing a special config:

CONFIG_NETFS_SUPPORTS=y
CONFIG_PROC_FS=n

The system crashes with something like:

[    3.766197] ------------[ cut here ]------------
[    3.766484] kernel BUG at mm/mempool.c:560!
[    3.766789] Oops: invalid opcode: 0000 [#1] SMP NOPTI
[    3.767123] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Tainted: G        W
[    3.767777] Tainted: [W]=WARN
[    3.767968] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
[    3.768523] RIP: 0010:mempool_alloc_slab.cold+0x17/0x19
[    3.768847] Code: 50 fe ff 58 5b 5d 41 5c 41 5d 41 5e 41 5f e9 93 95 13 00
[    3.769977] RSP: 0018:ffffc90000013998 EFLAGS: 00010286
[    3.770315] RAX: 000000000000002f RBX: ffff888100ba8640 RCX: 0000000000000000
[    3.770749] RDX: 0000000000000000 RSI: 0000000000000003 RDI: 00000000ffffffff
[    3.771217] RBP: 0000000000092880 R08: 0000000000000000 R09: ffffc90000013828
[    3.771664] R10: 0000000000000001 R11: 00000000ffffffea R12: 0000000000092cc0
[    3.772117] R13: 0000000000000400 R14: ffff8881004b1620 R15: ffffea0004ef7e40
[    3.772554] FS:  0000000000000000(0000) GS:ffff8881b5f3c000(0000) knlGS:0000000000000000
[    3.773061] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    3.773443] CR2: ffffffff830901b4 CR3: 0000000004296001 CR4: 0000000000770ef0
[    3.773884] PKRU: 55555554
[    3.774058] Call Trace:
[    3.774232]  <TASK>
[    3.774371]  mempool_alloc_noprof+0x6a/0x190
[    3.774649]  ? _printk+0x57/0x80
[    3.774862]  netfs_alloc_request+0x85/0x2ce
[    3.775147]  netfs_readahead+0x28/0x170
[    3.775395]  read_pages+0x6c/0x350
[    3.775623]  ? srso_alias_return_thunk+0x5/0xfbef5
[    3.775928]  page_cache_ra_unbounded+0x1bd/0x2a0
[    3.776247]  filemap_get_pages+0x139/0x970
[    3.776510]  ? srso_alias_return_thunk+0x5/0xfbef5
[    3.776820]  filemap_read+0xf9/0x580
[    3.777054]  ? srso_alias_return_thunk+0x5/0xfbef5
[    3.777368]  ? srso_alias_return_thunk+0x5/0xfbef5
[    3.777674]  ? find_held_lock+0x32/0x90
[    3.777929]  ? netfs_start_io_read+0x19/0x70
[    3.778221]  ? netfs_start_io_read+0x19/0x70
[    3.778489]  ? srso_alias_return_thunk+0x5/0xfbef5
[    3.778800]  ? lock_acquired+0x1e6/0x450
[    3.779054]  ? srso_alias_return_thunk+0x5/0xfbef5
[    3.779379]  netfs_buffered_read_iter+0x57/0x80
[    3.779670]  __kernel_read+0x158/0x2c0
[    3.779927]  bprm_execve+0x300/0x7a0
[    3.780185]  kernel_execve+0x10c/0x140
[    3.780423]  ? __pfx_kernel_init+0x10/0x10
[    3.780690]  kernel_init+0xd5/0x150
[    3.780910]  ret_from_fork+0x2d/0x50
[    3.781156]  ? __pfx_kernel_init+0x10/0x10
[    3.781414]  ret_from_fork_asm+0x1a/0x30
[    3.781677]  </TASK>
[    3.781823] Modules linked in:
[    3.782065] ---[ end trace 0000000000000000 ]---

This is caused by the following error path in netfs_init():

        if (!proc_mkdir("fs/netfs", NULL))
                goto error_proc;

Fix this by adding ifdef in netfs_main(), so that /proc/fs/netfs is only
created with CONFIG_PROC_FS.

Signed-off-by: Song Liu <[email protected]>
Link: https://lore.kernel.org/[email protected]
Acked-by: David Howells <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>
y86-dev pushed a commit that referenced this pull request Apr 21, 2025
SMC consists of two sockets: smc_sock and kernel TCP socket.

Currently, there are two ways of creating the sockets, and syzbot reported
a lockdep splat [0] for the newer way introduced by commit d25a92c
("net/smc: Introduce IPPROTO_SMC").

  socket(AF_SMC             , SOCK_STREAM, SMCPROTO_SMC or SMCPROTO_SMC6)
  socket(AF_INET or AF_INET6, SOCK_STREAM, IPPROTO_SMC)

When a socket is allocated, sock_lock_init() sets a lockdep lock class to
sk->sk_lock.slock based on its protocol family.  In the IPPROTO_SMC case,
AF_INET or AF_INET6 lock class is assigned to smc_sock.

The repro sets IPV6_JOIN_ANYCAST for IPv6 UDP and SMC socket and exercises
smc_switch_to_fallback() for IPPROTO_SMC.

  1. smc_switch_to_fallback() is called under lock_sock() and holds
     smc->clcsock_release_lock.

      sk_lock-AF_INET6 -> &smc->clcsock_release_lock
      (sk_lock-AF_SMC)

  2. Setting IPV6_JOIN_ANYCAST to SMC holds smc->clcsock_release_lock
     and calls setsockopt() for the kernel TCP socket, which holds RTNL
     and the kernel socket's lock_sock().

      &smc->clcsock_release_lock -> rtnl_mutex (-> k-sk_lock-AF_INET6)

  3. Setting IPV6_JOIN_ANYCAST to UDP holds RTNL and lock_sock().

      rtnl_mutex -> sk_lock-AF_INET6

Then, lockdep detects a false-positive circular locking,

  .-> sk_lock-AF_INET6 -> &smc->clcsock_release_lock -> rtnl_mutex -.
  `-----------------------------------------------------------------'

but IPPROTO_SMC should have the same locking rule as AF_SMC.

      sk_lock-AF_SMC   -> &smc->clcsock_release_lock -> rtnl_mutex -> k-sk_lock-AF_INET6

Let's set the same lock class for smc_sock.

Given AF_SMC uses the same lock class for SMCPROTO_SMC and SMCPROTO_SMC6,
we do not need to separate the class for AF_INET and AF_INET6.

[0]:
WARNING: possible circular locking dependency detected
6.14.0-rc3-syzkaller-00267-gff202c5028a1 #0 Not tainted

syz.4.1528/11571 is trying to acquire lock:
ffffffff8fef8de8 (rtnl_mutex){+.+.}-{4:4}, at: ipv6_sock_ac_close+0xd9/0x110 net/ipv6/anycast.c:220

but task is already holding lock:
ffff888027f596a8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_clcsock_release+0x75/0xe0 net/smc/smc_close.c:30

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

 -> Rust-for-Linux#2 (&smc->clcsock_release_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
       smc_switch_to_fallback+0x2d/0xa00 net/smc/af_smc.c:903
       smc_sendmsg+0x13d/0x520 net/smc/af_smc.c:2781
       sock_sendmsg_nosec net/socket.c:718 [inline]
       __sock_sendmsg net/socket.c:733 [inline]
       ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2573
       ___sys_sendmsg+0x135/0x1e0 net/socket.c:2627
       __sys_sendmsg+0x16e/0x220 net/socket.c:2659
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

 -> #1 (sk_lock-AF_INET6){+.+.}-{0:0}:
       lock_sock_nested+0x3a/0xf0 net/core/sock.c:3645
       lock_sock include/net/sock.h:1624 [inline]
       sockopt_lock_sock net/core/sock.c:1133 [inline]
       sockopt_lock_sock+0x54/0x70 net/core/sock.c:1124
       do_ipv6_setsockopt+0x2160/0x4520 net/ipv6/ipv6_sockglue.c:567
       ipv6_setsockopt+0xcb/0x170 net/ipv6/ipv6_sockglue.c:993
       udpv6_setsockopt+0x7d/0xd0 net/ipv6/udp.c:1850
       do_sock_setsockopt+0x222/0x480 net/socket.c:2303
       __sys_setsockopt+0x1a0/0x230 net/socket.c:2328
       __do_sys_setsockopt net/socket.c:2334 [inline]
       __se_sys_setsockopt net/socket.c:2331 [inline]
       __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2331
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

 -> #0 (rtnl_mutex){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3163 [inline]
       check_prevs_add kernel/locking/lockdep.c:3282 [inline]
       validate_chain kernel/locking/lockdep.c:3906 [inline]
       __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228
       lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
       ipv6_sock_ac_close+0xd9/0x110 net/ipv6/anycast.c:220
       inet6_release+0x47/0x70 net/ipv6/af_inet6.c:485
       __sock_release net/socket.c:647 [inline]
       sock_release+0x8e/0x1d0 net/socket.c:675
       smc_clcsock_release+0xb7/0xe0 net/smc/smc_close.c:34
       __smc_release+0x5c2/0x880 net/smc/af_smc.c:301
       smc_release+0x1fc/0x5f0 net/smc/af_smc.c:344
       __sock_release+0xb0/0x270 net/socket.c:647
       sock_close+0x1c/0x30 net/socket.c:1398
       __fput+0x3ff/0xb70 fs/file_table.c:464
       task_work_run+0x14e/0x250 kernel/task_work.c:227
       resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
       exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
       exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
       __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
       syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218
       do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  rtnl_mutex --> sk_lock-AF_INET6 --> &smc->clcsock_release_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&smc->clcsock_release_lock);
                               lock(sk_lock-AF_INET6);
                               lock(&smc->clcsock_release_lock);
  lock(rtnl_mutex);

 *** DEADLOCK ***

2 locks held by syz.4.1528/11571:
 #0: ffff888077e88208 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline]
 #0: ffff888077e88208 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:646
 #1: ffff888027f596a8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_clcsock_release+0x75/0xe0 net/smc/smc_close.c:30

stack backtrace:
CPU: 0 UID: 0 PID: 11571 Comm: syz.4.1528 Not tainted 6.14.0-rc3-syzkaller-00267-gff202c5028a1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_circular_bug+0x490/0x760 kernel/locking/lockdep.c:2076
 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2208
 check_prev_add kernel/locking/lockdep.c:3163 [inline]
 check_prevs_add kernel/locking/lockdep.c:3282 [inline]
 validate_chain kernel/locking/lockdep.c:3906 [inline]
 __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228
 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
 ipv6_sock_ac_close+0xd9/0x110 net/ipv6/anycast.c:220
 inet6_release+0x47/0x70 net/ipv6/af_inet6.c:485
 __sock_release net/socket.c:647 [inline]
 sock_release+0x8e/0x1d0 net/socket.c:675
 smc_clcsock_release+0xb7/0xe0 net/smc/smc_close.c:34
 __smc_release+0x5c2/0x880 net/smc/af_smc.c:301
 smc_release+0x1fc/0x5f0 net/smc/af_smc.c:344
 __sock_release+0xb0/0x270 net/socket.c:647
 sock_close+0x1c/0x30 net/socket.c:1398
 __fput+0x3ff/0xb70 fs/file_table.c:464
 task_work_run+0x14e/0x250 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8b4b38d169
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe4efd22d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00000000000b14a3 RCX: 00007f8b4b38d169
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f8b4b5a7ba0 R08: 0000000000000001 R09: 000000114efd25cf
R10: 00007f8b4b200000 R11: 0000000000000246 R12: 00007f8b4b5a5fac
R13: 00007f8b4b5a5fa0 R14: ffffffffffffffff R15: 00007ffe4efd23f0
 </TASK>

Fixes: d25a92c ("net/smc: Introduce IPPROTO_SMC")
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=be6f4b383534d88989f7
Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Wenjia Zhang <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
y86-dev pushed a commit that referenced this pull request Apr 21, 2025
When i2c-cros-ec-tunnel and the EC driver are built-in, the EC parent
device will not be found, leading to NULL pointer dereference.

That can also be reproduced by unbinding the controller driver and then
loading i2c-cros-ec-tunnel module (or binding the device).

[  271.991245] BUG: kernel NULL pointer dereference, address: 0000000000000058
[  271.998215] #PF: supervisor read access in kernel mode
[  272.003351] #PF: error_code(0x0000) - not-present page
[  272.008485] PGD 0 P4D 0
[  272.011022] Oops: Oops: 0000 [#1] SMP NOPTI
[  272.015207] CPU: 0 UID: 0 PID: 3859 Comm: insmod Tainted: G S                  6.15.0-rc1-00004-g44722359ed83 Rust-for-Linux#30 PREEMPT(full)  3c7fb39a552e7d949de2ad921a7d6588d3a4fdc5
[  272.030312] Tainted: [S]=CPU_OUT_OF_SPEC
[  272.034233] Hardware name: HP Berknip/Berknip, BIOS Google_Berknip.13434.356.0 05/17/2021
[  272.042400] RIP: 0010:ec_i2c_probe+0x2b/0x1c0 [i2c_cros_ec_tunnel]
[  272.048577] Code: 1f 44 00 00 41 57 41 56 41 55 41 54 53 48 83 ec 10 65 48 8b 05 06 a0 6c e7 48 89 44 24 08 4c 8d 7f 10 48 8b 47 50 4c 8b 60 78 <49> 83 7c 24 58 00 0f 84 2f 01 00 00 48 89 fb be 30 06 00 00 4c 9
[  272.067317] RSP: 0018:ffffa32082a03940 EFLAGS: 00010282
[  272.072541] RAX: ffff969580b6a810 RBX: ffff969580b68c10 RCX: 0000000000000000
[  272.079672] RDX: 0000000000000000 RSI: 0000000000000282 RDI: ffff969580b68c00
[  272.086804] RBP: 00000000fffffdfb R08: 0000000000000000 R09: 0000000000000000
[  272.093936] R10: 0000000000000000 R11: ffffffffc0600000 R12: 0000000000000000
[  272.101067] R13: ffffffffa666fbb8 R14: ffffffffc05b5528 R15: ffff969580b68c10
[  272.108198] FS:  00007b930906fc40(0000) GS:ffff969603149000(0000) knlGS:0000000000000000
[  272.116282] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  272.122024] CR2: 0000000000000058 CR3: 000000012631c000 CR4: 00000000003506f0
[  272.129155] Call Trace:
[  272.131606]  <TASK>
[  272.133709]  ? acpi_dev_pm_attach+0xdd/0x110
[  272.137985]  platform_probe+0x69/0xa0
[  272.141652]  really_probe+0x152/0x310
[  272.145318]  __driver_probe_device+0x77/0x110
[  272.149678]  driver_probe_device+0x1e/0x190
[  272.153864]  __driver_attach+0x10b/0x1e0
[  272.157790]  ? driver_attach+0x20/0x20
[  272.161542]  bus_for_each_dev+0x107/0x150
[  272.165553]  bus_add_driver+0x15d/0x270
[  272.169392]  driver_register+0x65/0x110
[  272.173232]  ? cleanup_module+0xa80/0xa80 [i2c_cros_ec_tunnel 3a00532f3f4af4a9eade753f86b0f8dd4e4e5698]
[  272.182617]  do_one_initcall+0x110/0x350
[  272.186543]  ? security_kernfs_init_security+0x49/0xd0
[  272.191682]  ? __kernfs_new_node+0x1b9/0x240
[  272.195954]  ? security_kernfs_init_security+0x49/0xd0
[  272.201093]  ? __kernfs_new_node+0x1b9/0x240
[  272.205365]  ? kernfs_link_sibling+0x105/0x130
[  272.209810]  ? kernfs_next_descendant_post+0x1c/0xa0
[  272.214773]  ? kernfs_activate+0x57/0x70
[  272.218699]  ? kernfs_add_one+0x118/0x160
[  272.222710]  ? __kernfs_create_file+0x71/0xa0
[  272.227069]  ? sysfs_add_bin_file_mode_ns+0xd6/0x110
[  272.232033]  ? internal_create_group+0x453/0x4a0
[  272.236651]  ? __vunmap_range_noflush+0x214/0x2d0
[  272.241355]  ? __free_frozen_pages+0x1dc/0x420
[  272.245799]  ? free_vmap_area_noflush+0x10a/0x1c0
[  272.250505]  ? load_module+0x1509/0x16f0
[  272.254431]  do_init_module+0x60/0x230
[  272.258181]  __se_sys_finit_module+0x27a/0x370
[  272.262627]  do_syscall_64+0x6a/0xf0
[  272.266206]  ? do_syscall_64+0x76/0xf0
[  272.269956]  ? irqentry_exit_to_user_mode+0x79/0x90
[  272.274836]  entry_SYSCALL_64_after_hwframe+0x55/0x5d
[  272.279887] RIP: 0033:0x7b9309168d39
[  272.283466] Code: 5b 41 5c 5d c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d af 40 0c 00 f7 d8 64 89 01 8
[  272.302210] RSP: 002b:00007fff50f1a288 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[  272.309774] RAX: ffffffffffffffda RBX: 000058bf9b50f6d0 RCX: 00007b9309168d39
[  272.316905] RDX: 0000000000000000 RSI: 000058bf6c103a77 RDI: 0000000000000003
[  272.324036] RBP: 00007fff50f1a2e0 R08: 00007fff50f19218 R09: 0000000021ec4150
[  272.331166] R10: 000058bf9b50f7f0 R11: 0000000000000246 R12: 0000000000000000
[  272.338296] R13: 00000000fffffffe R14: 0000000000000000 R15: 000058bf6c103a77
[  272.345428]  </TASK>
[  272.347617] Modules linked in: i2c_cros_ec_tunnel(+)
[  272.364585] gsmi: Log Shutdown Reason 0x03

Returning -EPROBE_DEFER will allow the device to be bound once the
controller is bound, in the case of built-in drivers.

Fixes: 9d230c9 ("i2c: ChromeOS EC tunnel driver")
Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
Cc: <[email protected]> # v3.16+
Signed-off-by: Andi Shyti <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
y86-dev pushed a commit that referenced this pull request Apr 21, 2025
ktest recently reported crashes while running several buffered io tests
with __alloc_tagging_slab_alloc_hook() at the top of the crash call stack.
The signature indicates an invalid address dereference with low bits of
slab->obj_exts being set. The bits were outside of the range used by
page_memcg_data_flags and objext_flags and hence were not masked out
by slab_obj_exts() when obtaining the pointer stored in slab->obj_exts.
The typical crash log looks like this:

00510 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
00510 Mem abort info:
00510   ESR = 0x0000000096000045
00510   EC = 0x25: DABT (current EL), IL = 32 bits
00510   SET = 0, FnV = 0
00510   EA = 0, S1PTW = 0
00510   FSC = 0x05: level 1 translation fault
00510 Data abort info:
00510   ISV = 0, ISS = 0x00000045, ISS2 = 0x00000000
00510   CM = 0, WnR = 1, TnD = 0, TagAccess = 0
00510   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
00510 user pgtable: 4k pages, 39-bit VAs, pgdp=0000000104175000
00510 [0000000000000010] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
00510 Internal error: Oops: 0000000096000045 [#1]  SMP
00510 Modules linked in:
00510 CPU: 10 UID: 0 PID: 7692 Comm: cat Not tainted 6.15.0-rc1-ktest-g189e17946605 #19327 NONE
00510 Hardware name: linux,dummy-virt (DT)
00510 pstate: 20001005 (nzCv daif -PAN -UAO -TCO -DIT +SSBS BTYPE=--)
00510 pc : __alloc_tagging_slab_alloc_hook+0xe0/0x190
00510 lr : __kmalloc_noprof+0x150/0x310
00510 sp : ffffff80c87df6c0
00510 x29: ffffff80c87df6c0 x28: 000000000013d1ff x27: 000000000013d200
00510 x26: ffffff80c87df9e0 x25: 0000000000000000 x24: 0000000000000001
00510 x23: ffffffc08041953c x22: 000000000000004c x21: ffffff80c0002180
00510 x20: fffffffec3120840 x19: ffffff80c4821000 x18: 0000000000000000
00510 x17: fffffffec3d02f00 x16: fffffffec3d02e00 x15: fffffffec3d00700
00510 x14: fffffffec3d00600 x13: 0000000000000200 x12: 0000000000000006
00510 x11: ffffffc080bb86c0 x10: 0000000000000000 x9 : ffffffc080201e58
00510 x8 : ffffff80c4821060 x7 : 0000000000000000 x6 : 0000000055555556
00510 x5 : 0000000000000001 x4 : 0000000000000010 x3 : 0000000000000060
00510 x2 : 0000000000000000 x1 : ffffffc080f50cf8 x0 : ffffff80d801d000
00510 Call trace:
00510  __alloc_tagging_slab_alloc_hook+0xe0/0x190 (P)
00510  __kmalloc_noprof+0x150/0x310
00510  __bch2_folio_create+0x5c/0xf8
00510  bch2_folio_create+0x2c/0x40
00510  bch2_readahead+0xc0/0x460
00510  read_pages+0x7c/0x230
00510  page_cache_ra_order+0x244/0x3a8
00510  page_cache_async_ra+0x124/0x170
00510  filemap_readahead.isra.0+0x58/0xa0
00510  filemap_get_pages+0x454/0x7b0
00510  filemap_read+0xdc/0x418
00510  bch2_read_iter+0x100/0x1b0
00510  vfs_read+0x214/0x300
00510  ksys_read+0x6c/0x108
00510  __arm64_sys_read+0x20/0x30
00510  invoke_syscall.constprop.0+0x54/0xe8
00510  do_el0_svc+0x44/0xc8
00510  el0_svc+0x18/0x58
00510  el0t_64_sync_handler+0x104/0x130
00510  el0t_64_sync+0x154/0x158
00510 Code: d5384100 f9401c01 b9401aa3 b40002e1 (f8227881)
00510 ---[ end trace 0000000000000000 ]---
00510 Kernel panic - not syncing: Oops: Fatal exception
00510 SMP: stopping secondary CPUs
00510 Kernel Offset: disabled
00510 CPU features: 0x0000,000000e0,00000410,8240500b
00510 Memory Limit: none

Investigation indicates that these bits are already set when we allocate
slab page and are not zeroed out after allocation. We are not yet sure
why these crashes start happening only recently but regardless of the
reason, not initializing a field that gets used later is wrong. Fix it
by initializing slab->obj_exts during slab page allocation.

Fixes: 21c690a ("mm: introduce slabobj_ext to support slab object extensions")
Reported-by: Kent Overstreet <[email protected]>
Tested-by: Kent Overstreet <[email protected]>
Signed-off-by: Suren Baghdasaryan <[email protected]>
Acked-by: Kent Overstreet <[email protected]>
Cc: [email protected]
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Vlastimil Babka <[email protected]>
y86-dev pushed a commit that referenced this pull request Apr 21, 2025
Running lib_ubsan.ko on arm64 (without CONFIG_UBSAN_TRAP) panics the
kernel:

[   31.616546] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: test_ubsan_out_of_bounds+0x158/0x158 [test_ubsan]
[   31.646817] CPU: 3 UID: 0 PID: 179 Comm: insmod Not tainted 6.15.0-rc2 #1 PREEMPT
[   31.648153] Hardware name: linux,dummy-virt (DT)
[   31.648970] Call trace:
[   31.649345]  show_stack+0x18/0x24 (C)
[   31.650960]  dump_stack_lvl+0x40/0x84
[   31.651559]  dump_stack+0x18/0x24
[   31.652264]  panic+0x138/0x3b4
[   31.652812]  __ktime_get_real_seconds+0x0/0x10
[   31.653540]  test_ubsan_load_invalid_value+0x0/0xa8 [test_ubsan]
[   31.654388]  init_module+0x24/0xff4 [test_ubsan]
[   31.655077]  do_one_initcall+0xd4/0x280
[   31.655680]  do_init_module+0x58/0x2b4

That happens because the test corrupts other data in the stack:
400:   d5384108        mrs     x8, sp_el0
404:   f9426d08        ldr     x8, [x8, torvalds#1240]
408:   f85f83a9        ldur    x9, [x29, #-8]
40c:   eb09011f        cmp     x8, x9
410:   54000301        b.ne    470 <test_ubsan_out_of_bounds+0x154>  // b.any

As there is no guarantee the compiler will order the local variables
as declared in the module:
        volatile char above[4] = { }; /* Protect surrounding memory. */
        volatile int arr[4];
        volatile char below[4] = { }; /* Protect surrounding memory. */

There is another problem where the out-of-bound index is 5 which is larger
than the extra surrounding memory for protection.

So, use a struct to enforce the ordering, and fix the index to be 4.
Also, remove some of the volatiles and rely on OPTIMIZER_HIDE_VAR()

Signed-off-by: Mostafa Saleh <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>
y86-dev pushed a commit that referenced this pull request Apr 21, 2025
Ido Schimmel says:

====================
fib_rules: Fix iif / oif matching on L3 master device

Patch #1 fixes a recently reported regression regarding FIB rules that
match on iif / oif being a VRF device.

Patch Rust-for-Linux#2 adds test cases to the FIB rules selftest.
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
y86-dev pushed a commit that referenced this pull request Apr 21, 2025
…pages

Alison reports an issue with fsdax when large extends end up using large
ZONE_DEVICE folios:

[  417.796271] BUG: kernel NULL pointer dereference, address: 0000000000000b00
[  417.796982] #PF: supervisor read access in kernel mode
[  417.797540] #PF: error_code(0x0000) - not-present page
[  417.798123] PGD 2a5c506 P4D 2a5c506 PUD 2a5c6067 PMD 0
[  417.798690] Oops: Oops: 0000 [#1] SMP NOPTI
[  417.799178] CPU: 5 UID: 0 PID: 1515 Comm: mmap Tainted: ...
[  417.800150] Tainted: [O]=OOT_MODULE
[  417.800583] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
[  417.801358] RIP: 0010:__lruvec_stat_mod_folio+0x7e/0x250
[  417.801948] Code: ...
[  417.803662] RSP: 0000:ffffc90002be3a08 EFLAGS: 00010206
[  417.804234] RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000000002
[  417.804984] RDX: ffffffff815652d7 RSI: 0000000000000000 RDI: ffffffff82a2beae
[  417.805689] RBP: ffffc90002be3a28 R08: 0000000000000000 R09: 0000000000000000
[  417.806384] R10: ffffea0007000040 R11: ffff888376ffe000 R12: 0000000000000001
[  417.807099] R13: 0000000000000012 R14: ffff88807fe4ab40 R15: ffff888029210580
[  417.807801] FS:  00007f339fa7a740(0000) GS:ffff8881fa9b9000(0000) knlGS:0000000000000000
[  417.808570] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  417.809193] CR2: 0000000000000b00 CR3: 000000002a4f0004 CR4: 0000000000370ef0
[  417.809925] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  417.810622] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  417.811353] Call Trace:
[  417.811709]  <TASK>
[  417.812038]  folio_add_file_rmap_ptes+0x143/0x230
[  417.812566]  insert_page_into_pte_locked+0x1ee/0x3c0
[  417.813132]  insert_page+0x78/0xf0
[  417.813558]  vmf_insert_page_mkwrite+0x55/0xa0
[  417.814088]  dax_fault_iter+0x484/0x7b0
[  417.814542]  dax_iomap_pte_fault+0x1ca/0x620
[  417.815055]  dax_iomap_fault+0x39/0x40
[  417.815499]  __xfs_write_fault+0x139/0x380
[  417.815995]  ? __handle_mm_fault+0x5e5/0x1a60
[  417.816483]  xfs_write_fault+0x41/0x50
[  417.816966]  xfs_filemap_fault+0x3b/0xe0
[  417.817424]  __do_fault+0x31/0x180
[  417.817859]  __handle_mm_fault+0xee1/0x1a60
[  417.818325]  ? debug_smp_processor_id+0x17/0x20
[  417.818844]  handle_mm_fault+0xe1/0x2b0
[...]

The issue is that when we split a large ZONE_DEVICE folio to order-0 ones,
we don't reset the order/_nr_pages.  As folio->_nr_pages overlays
page[1]->memcg_data, once page[1] is a folio, it suddenly looks like it
has folio->memcg_data set.  And we never manually initialize
folio->memcg_data in fsdax code, because we never expect it to be set at
all.

When __lruvec_stat_mod_folio() then stumbles over such a folio, it tries
to use folio->memcg_data (because it's non-NULL) but it does not actually
point at a memcg, resulting in the problem.

Alison also observed that these folios sometimes have "locked" set, which
is rather concerning (folios locked from the beginning ...).  The reason
is that the order for large folios is stored in page[1]->flags, which
become the folio->flags of a new small folio.

Let's fix it by adding a folio helper to clear order/_nr_pages for
splitting purposes.

Maybe we should reinitialize other large folio flags / folio members as
well when splitting, because they might similarly cause harm once page[1]
becomes a folio?  At least other flags in PAGE_FLAGS_SECOND should not be
set for fsdax, so at least page[1]->flags might be as expected with this
fix.

From a quick glimpse, initializing ->mapping, ->pgmap and ->share should
re-initialize most things from a previous page[1] used by large folios
that fsdax cares about.  For example folio->private might not get
reinitialized, but maybe that's not relevant -- no traces of it's use in
fsdax code.  Needs a closer look.

Another thing that should be considered in the future is performing
similar checks as we perform in free_tail_page_prepare()
-- checking pincount etc.
-- when freeing a large fsdax folio.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 4996fc5 ("mm: let _folio_nr_pages overlay memcg_data in first tail page")
Fixes: 38607c6 ("fs/dax: properly refcount fs dax pages")
Signed-off-by: David Hildenbrand <[email protected]>
Reported-by: Alison Schofield <[email protected]>
Closes: https://lkml.kernel.org/r/[email protected]
Tested-by: Alison Schofield <[email protected]>
Reviewed-by: Dan Williams <[email protected]>
Tested-by: "Darrick J. Wong" <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
y86-dev pushed a commit that referenced this pull request Apr 21, 2025
Communicating with the hypervisor using the shared GHCB page requires
clearing the C bit in the mapping of that page. When executing in the
context of the EFI boot services, the page tables are owned by the
firmware, and this manipulation is not possible.

So switch to a different API for accepting memory in SEV-SNP guests, one
which is actually supported at the point during boot where the EFI stub
may need to accept memory, but the SEV-SNP init code has not executed
yet.

For simplicity, also switch the memory acceptance carried out by the
decompressor when not booting via EFI - this only involves the
allocation for the decompressed kernel, and is generally only called
after kexec, as normal boot will jump straight into the kernel from the
EFI stub.

Fixes: 6c32117 ("x86/sev: Add SNP-specific unaccepted memory support")
Tested-by: Tom Lendacky <[email protected]>
Co-developed-by: Tom Lendacky <[email protected]>
Signed-off-by: Tom Lendacky <[email protected]>
Signed-off-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: <[email protected]>
Cc: Dionna Amalie Glaze <[email protected]>
Cc: Kevin Loughlin <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected] # discussion thread #1
Link: https://lore.kernel.org/r/[email protected] # discussion thread Rust-for-Linux#2
Link: https://lore.kernel.org/r/[email protected] # final submission
y86-dev pushed a commit that referenced this pull request May 20, 2025
A vmemmap altmap is a device-provided region used to provide
backing storage for struct pages. For each namespace, the altmap
should belong to that same namespace. If the namespaces are
created unaligned, there is a chance that the section vmemmap
start address could also be unaligned. If the section vmemmap
start address is unaligned, the altmap page allocated from the
current namespace might be used by the previous namespace also.
During the free operation, since the altmap is shared between two
namespaces, the previous namespace may detect that the page does
not belong to its altmap and incorrectly assume that the page is a
normal page. It then attempts to free the normal page, which leads
to a kernel crash.

Kernel attempted to read user page (18) - exploit attempt? (uid: 0)
BUG: Kernel NULL pointer dereference on read at 0x00000018
Faulting instruction address: 0xc000000000530c7c
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
CPU: 32 PID: 2104 Comm: ndctl Kdump: loaded Tainted: G        W
NIP:  c000000000530c7c LR: c000000000530e00 CTR: 0000000000007ffe
REGS: c000000015e57040 TRAP: 0300   Tainted: G        W
MSR:  800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE>  CR: 84482404
CFAR: c000000000530dfc DAR: 0000000000000018 DSISR: 40000000 IRQMASK: 0
GPR00: c000000000530e00 c000000015e572e0 c000000002c5cb00 c00c000101008040
GPR04: 0000000000000000 0000000000000007 0000000000000001 000000000000001f
GPR08: 0000000000000005 0000000000000000 0000000000000018 0000000000002000
GPR12: c0000000001d2fb0 c0000060de6b0080 0000000000000000 c0000060dbf90020
GPR16: c00c000101008000 0000000000000001 0000000000000000 c000000125b20f00
GPR20: 0000000000000001 0000000000000000 ffffffffffffffff c00c000101007fff
GPR24: 0000000000000001 0000000000000000 0000000000000000 0000000000000000
GPR28: 0000000004040201 0000000000000001 0000000000000000 c00c000101008040
NIP [c000000000530c7c] get_pfnblock_flags_mask+0x7c/0xd0
LR [c000000000530e00] free_unref_page_prepare+0x130/0x4f0
Call Trace:
free_unref_page+0x50/0x1e0
free_reserved_page+0x40/0x68
free_vmemmap_pages+0x98/0xe0
remove_pte_table+0x164/0x1e8
remove_pmd_table+0x204/0x2c8
remove_pud_table+0x1c4/0x288
remove_pagetable+0x1c8/0x310
vmemmap_free+0x24/0x50
section_deactivate+0x28c/0x2a0
__remove_pages+0x84/0x110
arch_remove_memory+0x38/0x60
memunmap_pages+0x18c/0x3d0
devm_action_release+0x30/0x50
release_nodes+0x68/0x140
devres_release_group+0x100/0x190
dax_pmem_compat_release+0x44/0x80 [dax_pmem_compat]
device_for_each_child+0x8c/0x100
[dax_pmem_compat_remove+0x2c/0x50 [dax_pmem_compat]
nvdimm_bus_remove+0x78/0x140 [libnvdimm]
device_remove+0x70/0xd0

Another issue is that if there is no altmap, a PMD-sized vmemmap
page will be allocated from RAM, regardless of the alignment of
the section start address. If the section start address is not
aligned to the PMD size, a VM_BUG_ON will be triggered when
setting the PMD-sized page to page table.

In this patch, we are aligning the section vmemmap start address
to PAGE_SIZE. After alignment, the start address will not be
part of the current namespace, and a normal page will be allocated
for the vmemmap mapping of the current section. For the remaining
sections, altmaps will be allocated. During the free operation,
the normal page will be correctly freed.

In the same way, a PMD_SIZE vmemmap page will be allocated only if
the section start address is PMD_SIZE-aligned; otherwise, it will
fall back to a PAGE-sized vmemmap allocation.

Without this patch
==================
NS1 start               NS2 start
 _________________________________________________________
|         NS1               |            NS2              |
 ---------------------------------------------------------
| Altmap| Altmap | .....|Altmap| Altmap | ...........
|  NS1  |  NS1   |      | NS2  |  NS2   |

In the above scenario, NS1 and NS2 are two namespaces. The vmemmap
for NS1 comes from Altmap NS1, which belongs to NS1, and the
vmemmap for NS2 comes from Altmap NS2, which belongs to NS2.

The vmemmap start for NS2 is not aligned, so Altmap NS2 is shared
by both NS1 and NS2. During the free operation in NS1, Altmap NS2
is not part of NS1's altmap, causing it to attempt to free an
invalid page.

With this patch
===============
NS1 start               NS2 start
 _________________________________________________________
|         NS1               |            NS2              |
 ---------------------------------------------------------
| Altmap| Altmap | .....| Normal | Altmap | Altmap |.......
|  NS1  |  NS1   |      |  Page  |  NS2   |  NS2   |

If the vmemmap start for NS2 is not aligned then we are allocating
a normal page. NS1 and NS2 vmemmap will be freed correctly.

Fixes: 368a059 ("powerpc/book3s64/vmemmap: switch radix to use a different vmemmap handling function")
Co-developed-by: Ritesh Harjani (IBM) <[email protected]>
Signed-off-by: Ritesh Harjani (IBM) <[email protected]>
Signed-off-by: Donet Tom <[email protected]>
Signed-off-by: Madhavan Srinivasan <[email protected]>
Link: https://patch.msgid.link/8f98ec2b442977c618f7256cec88eb17dde3f2b9.1741609795.git.donettom@linux.ibm.com
y86-dev pushed a commit that referenced this pull request May 20, 2025
for_each_present_section_nr() was introduced to add_boot_memory_block()
by commit 61659ef ("drivers/base/memory: improve add_boot_memory_block()").
It causes unnecessary overhead when the present sections are really
sparse. next_present_section_nr() called by the macro to find the next
present section, which is far away from the spanning sections in the
specified block. Too much time consumed by next_present_section_nr()
in this case, which can lead to softlockup as observed by Aditya Gupta
on IBM Power10 machine.

  watchdog: BUG: soft lockup - CPU#248 stuck for 22s! [swapper/248:1]
  Modules linked in:
  CPU: 248 UID: 0 PID: 1 Comm: swapper/248 Not tainted 6.15.0-rc1-next-20250408 #1 VOLUNTARY
  Hardware name: 9105-22A POWER10 (raw) 0x800200 opal:v7.1-107-gfda75d121942 PowerNV
  NIP:  c00000000209218c LR: c000000002092204 CTR: 0000000000000000
  REGS: c00040000418fa30 TRAP: 0900   Not tainted  (6.15.0-rc1-next-20250408)
  MSR:  9000000002009033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE>  CR: 28000428  XER: 00000000
  CFAR: 0000000000000000 IRQMASK: 0
  GPR00: c000000002092204 c00040000418fcd0 c000000001b08100 0000000000000040
  GPR04: 0000000000013e00 c000c03ffebabb00 0000000000c03fff c000400fff587f80
  GPR08: 0000000000000000 00000000001196f7 0000000000000000 0000000028000428
  GPR12: 0000000000000000 c000000002e80000 c00000000001007c 0000000000000000
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR24: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR28: c000000002df7f70 0000000000013dc0 c0000000011dd898 0000000008000000
  NIP [c00000000209218c] memory_dev_init+0x114/0x1e0
  LR [c000000002092204] memory_dev_init+0x18c/0x1e0
  Call Trace:
  [c00040000418fcd0] [c000000002092204] memory_dev_init+0x18c/0x1e0 (unreliable)
  [c00040000418fd50] [c000000002091348] driver_init+0x78/0xa4
  [c00040000418fd70] [c0000000020063ac] kernel_init_freeable+0x22c/0x370
  [c00040000418fde0] [c0000000000100a8] kernel_init+0x34/0x25c
  [c00040000418fe50] [c00000000000cd94] ret_from_kernel_user_thread+0x14/0x1c

Avoid the overhead by folding for_each_present_section_nr() to the outer
loop. add_boot_memory_block() is dropped after that.

Fixes: 61659ef ("drivers/base/memory: improve add_boot_memory_block()")
Closes: https://lore.kernel.org/linux-mm/[email protected]
Reported-by: Aditya Gupta <[email protected]>
Signed-off-by: Gavin Shan <[email protected]>
Acked-by: Oscar Salvador <[email protected]>
Tested-by: Aditya Gupta <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
There was a bug report about a NULL pointer dereference in
__btrfs_add_free_space_zoned() that ultimately happens because a
conversion from the default metadata profile DUP to a RAID1 profile on two
disks.

The stack trace has the following signature:

  BTRFS error (device sdc): zoned: write pointer offset mismatch of zones in raid1 profile
  BUG: kernel NULL pointer dereference, address: 0000000000000058
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
  RIP: 0010:__btrfs_add_free_space_zoned.isra.0+0x61/0x1a0
  RSP: 0018:ffffa236b6f3f6d0 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff96c8132f3400 RCX: 0000000000000001
  RDX: 0000000010000000 RSI: 0000000000000000 RDI: ffff96c8132f3410
  RBP: 0000000010000000 R08: 0000000000000003 R09: 0000000000000000
  R10: 0000000000000000 R11: 00000000ffffffff R12: 0000000000000000
  R13: ffff96c758f65a40 R14: 0000000000000001 R15: 000011aac0000000
  FS: 00007fdab1cb2900(0000) GS:ffff96e60ca00000(0000) knlGS:0000000000000000
  CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000058 CR3: 00000001a05ae000 CR4: 0000000000350ef0
  Call Trace:
  <TASK>
  ? __die_body.cold+0x19/0x27
  ? page_fault_oops+0x15c/0x2f0
  ? exc_page_fault+0x7e/0x180
  ? asm_exc_page_fault+0x26/0x30
  ? __btrfs_add_free_space_zoned.isra.0+0x61/0x1a0
  btrfs_add_free_space_async_trimmed+0x34/0x40
  btrfs_add_new_free_space+0x107/0x120
  btrfs_make_block_group+0x104/0x2b0
  btrfs_create_chunk+0x977/0xf20
  btrfs_chunk_alloc+0x174/0x510
  ? srso_return_thunk+0x5/0x5f
  btrfs_inc_block_group_ro+0x1b1/0x230
  btrfs_relocate_block_group+0x9e/0x410
  btrfs_relocate_chunk+0x3f/0x130
  btrfs_balance+0x8ac/0x12b0
  ? srso_return_thunk+0x5/0x5f
  ? srso_return_thunk+0x5/0x5f
  ? __kmalloc_cache_noprof+0x14c/0x3e0
  btrfs_ioctl+0x2686/0x2a80
  ? srso_return_thunk+0x5/0x5f
  ? ioctl_has_perm.constprop.0.isra.0+0xd2/0x120
  __x64_sys_ioctl+0x97/0xc0
  do_syscall_64+0x82/0x160
  ? srso_return_thunk+0x5/0x5f
  ? __memcg_slab_free_hook+0x11a/0x170
  ? srso_return_thunk+0x5/0x5f
  ? kmem_cache_free+0x3f0/0x450
  ? srso_return_thunk+0x5/0x5f
  ? srso_return_thunk+0x5/0x5f
  ? syscall_exit_to_user_mode+0x10/0x210
  ? srso_return_thunk+0x5/0x5f
  ? do_syscall_64+0x8e/0x160
  ? sysfs_emit+0xaf/0xc0
  ? srso_return_thunk+0x5/0x5f
  ? srso_return_thunk+0x5/0x5f
  ? seq_read_iter+0x207/0x460
  ? srso_return_thunk+0x5/0x5f
  ? vfs_read+0x29c/0x370
  ? srso_return_thunk+0x5/0x5f
  ? srso_return_thunk+0x5/0x5f
  ? syscall_exit_to_user_mode+0x10/0x210
  ? srso_return_thunk+0x5/0x5f
  ? do_syscall_64+0x8e/0x160
  ? srso_return_thunk+0x5/0x5f
  ? exc_page_fault+0x7e/0x180
  entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7fdab1e0ca6d
  RSP: 002b:00007ffeb2b60c80 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fdab1e0ca6d
  RDX: 00007ffeb2b60d80 RSI: 00000000c4009420 RDI: 0000000000000003
  RBP: 00007ffeb2b60cd0 R08: 0000000000000000 R09: 0000000000000013
  R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
  R13: 00007ffeb2b6343b R14: 00007ffeb2b60d80 R15: 0000000000000001
  </TASK>
  CR2: 0000000000000058
  ---[ end trace 0000000000000000 ]---

The 1st line is the most interesting here:

 BTRFS error (device sdc): zoned: write pointer offset mismatch of zones in raid1 profile

When a RAID1 block-group is created and a write pointer mismatch between
the disks in the RAID set is detected, btrfs sets the alloc_offset to the
length of the block group marking it as full. Afterwards the code expects
that a balance operation will evacuate the data in this block-group and
repair the problems.

But before this is possible, the new space of this block-group will be
accounted in the free space cache. But in __btrfs_add_free_space_zoned()
it is being checked if it is a initial creation of a block group and if
not a reclaim decision will be made. But the decision if a block-group's
free space accounting is done for an initial creation depends on if the
size of the added free space is the whole length of the block-group and
the allocation offset is 0.

But as btrfs_load_block_group_zone_info() sets the allocation offset to
the zone capacity (i.e. marking the block-group as full) this initial
decision is not met, and the space_info pointer in the 'struct
btrfs_block_group' has not yet been assigned.

Fail creation of the block group and rely on manual user intervention to
re-balance the filesystem.

Afterwards the filesystem can be unmounted, mounted in degraded mode and
the missing device can be removed after a full balance of the filesystem.

Reported-by: 西木野羰基 <[email protected]>
Link: https://lore.kernel.org/linux-btrfs/CAB_b4sBhDe3tscz=duVyhc9hNE+gu=B8CrgLO152uMyanR8BEA@mail.gmail.com/
Fixes: b1934cd ("btrfs: zoned: handle broken write pointer on zones")
Reviewed-by: Anand Jain <[email protected]>
Signed-off-by: Johannes Thumshirn <[email protected]>
Signed-off-by: David Sterba <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
If we have a failure at create_reloc_inode(), under the 'out' label we
assign an error pointer to the 'inode' variable and then return a weird
pointer because we return the expression "&inode->vfs_inode":

   static noinline_for_stack struct inode *create_reloc_inode(
                                    const struct btrfs_block_group *group)
   {
       (...)
   out:
       (...)
       if (ret) {
            if (inode)
                  iput(&inode->vfs_inode);
            inode = ERR_PTR(ret);
       }
       return &inode->vfs_inode;
   }

This can make us return a pointer that is not an error pointer and make
the caller proceed as if an error didn't happen and later result in an
invalid memory access when dereferencing the inode pointer.
Syzbot reported reported such a case with the following stack trace:

   R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
   R13: 0000000000000000 R14: 431bde82d7b634db R15: 00007ffc55de5790
    </TASK>
   BTRFS info (device loop0): relocating block group 6881280 flags data|metadata
   Oops: general protection fault, probably for non-canonical address 0xdffffc0000000045: 0000 [#1] SMP KASAN NOPTI
   KASAN: null-ptr-deref in range [0x0000000000000228-0x000000000000022f]
   CPU: 0 UID: 0 PID: 5332 Comm: syz-executor215 Not tainted 6.14.0-syzkaller-13423-ga8662bcd2ff1 #0 PREEMPT(full)
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
   RIP: 0010:relocate_file_extent_cluster+0xe7/0x1750 fs/btrfs/relocation.c:2971
   Code: 00 74 08 (...)
   RSP: 0018:ffffc9000d3375e0 EFLAGS: 00010203
   RAX: 0000000000000045 RBX: 000000000000022c RCX: ffff888000562440
   RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880452db000
   RBP: ffffc9000d337870 R08: ffffffff84089251 R09: 0000000000000000
   R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
   R13: ffffffff9368a020 R14: 0000000000000394 R15: ffff8880452db000
   FS:  000055558bc7b380(0000) GS:ffff88808c596000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: 000055a7a192e740 CR3: 0000000036e2e000 CR4: 0000000000352ef0
   DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
   DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
   Call Trace:
    <TASK>
    relocate_block_group+0xa1e/0xd50 fs/btrfs/relocation.c:3657
    btrfs_relocate_block_group+0x777/0xd80 fs/btrfs/relocation.c:4011
    btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3511
    __btrfs_balance+0x1a93/0x25e0 fs/btrfs/volumes.c:4292
    btrfs_balance+0xbde/0x10c0 fs/btrfs/volumes.c:4669
    btrfs_ioctl_balance+0x3f5/0x660 fs/btrfs/ioctl.c:3586
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:906 [inline]
    __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   RIP: 0033:0x7fb4ef537dd9
   Code: 28 00 00 (...)
   RSP: 002b:00007ffc55de5728 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
   RAX: ffffffffffffffda RBX: 00007ffc55de5750 RCX: 00007fb4ef537dd9
   RDX: 0000200000000440 RSI: 00000000c4009420 RDI: 0000000000000003
   RBP: 0000000000000002 R08: 00007ffc55de54c6 R09: 00007ffc55de5770
   R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
   R13: 0000000000000000 R14: 431bde82d7b634db R15: 00007ffc55de5790
    </TASK>
   Modules linked in:
   ---[ end trace 0000000000000000 ]---
   RIP: 0010:relocate_file_extent_cluster+0xe7/0x1750 fs/btrfs/relocation.c:2971
   Code: 00 74 08 (...)
   RSP: 0018:ffffc9000d3375e0 EFLAGS: 00010203
   RAX: 0000000000000045 RBX: 000000000000022c RCX: ffff888000562440
   RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880452db000
   RBP: ffffc9000d337870 R08: ffffffff84089251 R09: 0000000000000000
   R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
   R13: ffffffff9368a020 R14: 0000000000000394 R15: ffff8880452db000
   FS:  000055558bc7b380(0000) GS:ffff88808c596000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: 000055a7a192e740 CR3: 0000000036e2e000 CR4: 0000000000352ef0
   DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
   DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
   ----------------
   Code disassembly (best guess):
      0:	00 74 08 48          	add    %dh,0x48(%rax,%rcx,1)
      4:	89 df                	mov    %ebx,%edi
      6:	e8 f8 36 24 fe       	call   0xfe243703
      b:	48 89 9c 24 30 01 00 	mov    %rbx,0x130(%rsp)
     12:	00
     13:	4c 89 74 24 28       	mov    %r14,0x28(%rsp)
     18:	4d 8b 76 10          	mov    0x10(%r14),%r14
     1c:	49 8d 9e 98 fe ff ff 	lea    -0x168(%r14),%rbx
     23:	48 89 d8             	mov    %rbx,%rax
     26:	48 c1 e8 03          	shr    $0x3,%rax
   * 2a:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
     2f:	74 08                	je     0x39
     31:	48 89 df             	mov    %rbx,%rdi
     34:	e8 ca 36 24 fe       	call   0xfe243703
     39:	4c 8b 3b             	mov    (%rbx),%r15
     3c:	48                   	rex.W
     3d:	8b                   	.byte 0x8b
     3e:	44                   	rex.R
     3f:	24                   	.byte 0x24

So fix this by returning the error immediately.

Reported-by: [email protected]
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Fixes: b204e5c ("btrfs: make btrfs_iget() return a btrfs inode instead")
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Filipe Manana <[email protected]>
Signed-off-by: David Sterba <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
There is a potential deadlock if we do report zones in an IO context, detailed
in below lockdep report. When one process do a report zones and another process
freezes the block device, the report zones side cannot allocate a tag because
the freeze is already started. This can thus result in new block group creation
to hang forever, blocking the write path.

Thankfully, a new block group should be created on empty zones. So, reporting
the zones is not necessary and we can set the write pointer = 0 and load the
zone capacity from the block layer using bdev_zone_capacity() helper.

 ======================================================
 WARNING: possible circular locking dependency detected
 6.14.0-rc1 Rust-for-Linux#252 Not tainted
 ------------------------------------------------------
 modprobe/1110 is trying to acquire lock:
 ffff888100ac83e0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: __flush_work+0x38f/0xb60

 but task is already holding lock:
 ffff8881205b6f20 (&q->q_usage_counter(queue)Rust-for-Linux#16){++++}-{0:0}, at: sd_remove+0x85/0x130

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> Rust-for-Linux#3 (&q->q_usage_counter(queue)Rust-for-Linux#16){++++}-{0:0}:
        blk_queue_enter+0x3d9/0x500
        blk_mq_alloc_request+0x47d/0x8e0
        scsi_execute_cmd+0x14f/0xb80
        sd_zbc_do_report_zones+0x1c1/0x470
        sd_zbc_report_zones+0x362/0xd60
        blkdev_report_zones+0x1b1/0x2e0
        btrfs_get_dev_zones+0x215/0x7e0 [btrfs]
        btrfs_load_block_group_zone_info+0x6d2/0x2c10 [btrfs]
        btrfs_make_block_group+0x36b/0x870 [btrfs]
        btrfs_create_chunk+0x147d/0x2320 [btrfs]
        btrfs_chunk_alloc+0x2ce/0xcf0 [btrfs]
        start_transaction+0xce6/0x1620 [btrfs]
        btrfs_uuid_scan_kthread+0x4ee/0x5b0 [btrfs]
        kthread+0x39d/0x750
        ret_from_fork+0x30/0x70
        ret_from_fork_asm+0x1a/0x30

 -> Rust-for-Linux#2 (&fs_info->dev_replace.rwsem){++++}-{4:4}:
        down_read+0x9b/0x470
        btrfs_map_block+0x2ce/0x2ce0 [btrfs]
        btrfs_submit_chunk+0x2d4/0x16c0 [btrfs]
        btrfs_submit_bbio+0x16/0x30 [btrfs]
        btree_write_cache_pages+0xb5a/0xf90 [btrfs]
        do_writepages+0x17f/0x7b0
        __writeback_single_inode+0x114/0xb00
        writeback_sb_inodes+0x52b/0xe00
        wb_writeback+0x1a7/0x800
        wb_workfn+0x12a/0xbd0
        process_one_work+0x85a/0x1460
        worker_thread+0x5e2/0xfc0
        kthread+0x39d/0x750
        ret_from_fork+0x30/0x70
        ret_from_fork_asm+0x1a/0x30

 -> #1 (&fs_info->zoned_meta_io_lock){+.+.}-{4:4}:
        __mutex_lock+0x1aa/0x1360
        btree_write_cache_pages+0x252/0xf90 [btrfs]
        do_writepages+0x17f/0x7b0
        __writeback_single_inode+0x114/0xb00
        writeback_sb_inodes+0x52b/0xe00
        wb_writeback+0x1a7/0x800
        wb_workfn+0x12a/0xbd0
        process_one_work+0x85a/0x1460
        worker_thread+0x5e2/0xfc0
        kthread+0x39d/0x750
        ret_from_fork+0x30/0x70
        ret_from_fork_asm+0x1a/0x30

 -> #0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}:
        __lock_acquire+0x2f52/0x5ea0
        lock_acquire+0x1b1/0x540
        __flush_work+0x3ac/0xb60
        wb_shutdown+0x15b/0x1f0
        bdi_unregister+0x172/0x5b0
        del_gendisk+0x841/0xa20
        sd_remove+0x85/0x130
        device_release_driver_internal+0x368/0x520
        bus_remove_device+0x1f1/0x3f0
        device_del+0x3bd/0x9c0
        __scsi_remove_device+0x272/0x340
        scsi_forget_host+0xf7/0x170
        scsi_remove_host+0xd2/0x2a0
        sdebug_driver_remove+0x52/0x2f0 [scsi_debug]
        device_release_driver_internal+0x368/0x520
        bus_remove_device+0x1f1/0x3f0
        device_del+0x3bd/0x9c0
        device_unregister+0x13/0xa0
        sdebug_do_remove_host+0x1fb/0x290 [scsi_debug]
        scsi_debug_exit+0x17/0x70 [scsi_debug]
        __do_sys_delete_module.isra.0+0x321/0x520
        do_syscall_64+0x93/0x180
        entry_SYSCALL_64_after_hwframe+0x76/0x7e

 other info that might help us debug this:

 Chain exists of:
   (work_completion)(&(&wb->dwork)->work) --> &fs_info->dev_replace.rwsem --> &q->q_usage_counter(queue)Rust-for-Linux#16

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&q->q_usage_counter(queue)Rust-for-Linux#16);
                                lock(&fs_info->dev_replace.rwsem);
                                lock(&q->q_usage_counter(queue)Rust-for-Linux#16);
   lock((work_completion)(&(&wb->dwork)->work));

  *** DEADLOCK ***

 5 locks held by modprobe/1110:
  #0: ffff88811f7bc108 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0x8f/0x520
  #1: ffff8881022ee0e0 (&shost->scan_mutex){+.+.}-{4:4}, at: scsi_remove_host+0x20/0x2a0
  Rust-for-Linux#2: ffff88811b4c4378 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0x8f/0x520
  Rust-for-Linux#3: ffff8881205b6f20 (&q->q_usage_counter(queue)Rust-for-Linux#16){++++}-{0:0}, at: sd_remove+0x85/0x130
  Rust-for-Linux#4: ffffffffa3284360 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xda/0xb60

 stack backtrace:
 CPU: 0 UID: 0 PID: 1110 Comm: modprobe Not tainted 6.14.0-rc1 Rust-for-Linux#252
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014
 Call Trace:
  <TASK>
  dump_stack_lvl+0x6a/0x90
  print_circular_bug.cold+0x1e0/0x274
  check_noncircular+0x306/0x3f0
  ? __pfx_check_noncircular+0x10/0x10
  ? mark_lock+0xf5/0x1650
  ? __pfx_check_irq_usage+0x10/0x10
  ? lockdep_lock+0xca/0x1c0
  ? __pfx_lockdep_lock+0x10/0x10
  __lock_acquire+0x2f52/0x5ea0
  ? __pfx___lock_acquire+0x10/0x10
  ? __pfx_mark_lock+0x10/0x10
  lock_acquire+0x1b1/0x540
  ? __flush_work+0x38f/0xb60
  ? __pfx_lock_acquire+0x10/0x10
  ? __pfx_lock_release+0x10/0x10
  ? mark_held_locks+0x94/0xe0
  ? __flush_work+0x38f/0xb60
  __flush_work+0x3ac/0xb60
  ? __flush_work+0x38f/0xb60
  ? __pfx_mark_lock+0x10/0x10
  ? __pfx___flush_work+0x10/0x10
  ? __pfx_wq_barrier_func+0x10/0x10
  ? __pfx___might_resched+0x10/0x10
  ? mark_held_locks+0x94/0xe0
  wb_shutdown+0x15b/0x1f0
  bdi_unregister+0x172/0x5b0
  ? __pfx_bdi_unregister+0x10/0x10
  ? up_write+0x1ba/0x510
  del_gendisk+0x841/0xa20
  ? __pfx_del_gendisk+0x10/0x10
  ? _raw_spin_unlock_irqrestore+0x35/0x60
  ? __pm_runtime_resume+0x79/0x110
  sd_remove+0x85/0x130
  device_release_driver_internal+0x368/0x520
  ? kobject_put+0x5d/0x4a0
  bus_remove_device+0x1f1/0x3f0
  device_del+0x3bd/0x9c0
  ? __pfx_device_del+0x10/0x10
  __scsi_remove_device+0x272/0x340
  scsi_forget_host+0xf7/0x170
  scsi_remove_host+0xd2/0x2a0
  sdebug_driver_remove+0x52/0x2f0 [scsi_debug]
  ? kernfs_remove_by_name_ns+0xc0/0xf0
  device_release_driver_internal+0x368/0x520
  ? kobject_put+0x5d/0x4a0
  bus_remove_device+0x1f1/0x3f0
  device_del+0x3bd/0x9c0
  ? __pfx_device_del+0x10/0x10
  ? __pfx___mutex_unlock_slowpath+0x10/0x10
  device_unregister+0x13/0xa0
  sdebug_do_remove_host+0x1fb/0x290 [scsi_debug]
  scsi_debug_exit+0x17/0x70 [scsi_debug]
  __do_sys_delete_module.isra.0+0x321/0x520
  ? __pfx___do_sys_delete_module.isra.0+0x10/0x10
  ? __pfx_slab_free_after_rcu_debug+0x10/0x10
  ? kasan_save_stack+0x2c/0x50
  ? kasan_record_aux_stack+0xa3/0xb0
  ? __call_rcu_common.constprop.0+0xc4/0xfb0
  ? kmem_cache_free+0x3a0/0x590
  ? __x64_sys_close+0x78/0xd0
  do_syscall_64+0x93/0x180
  ? lock_is_held_type+0xd5/0x130
  ? __call_rcu_common.constprop.0+0x3c0/0xfb0
  ? lockdep_hardirqs_on+0x78/0x100
  ? __call_rcu_common.constprop.0+0x3c0/0xfb0
  ? __pfx___call_rcu_common.constprop.0+0x10/0x10
  ? kmem_cache_free+0x3a0/0x590
  ? lockdep_hardirqs_on_prepare+0x16d/0x400
  ? do_syscall_64+0x9f/0x180
  ? lockdep_hardirqs_on+0x78/0x100
  ? do_syscall_64+0x9f/0x180
  ? __pfx___x64_sys_openat+0x10/0x10
  ? lockdep_hardirqs_on_prepare+0x16d/0x400
  ? do_syscall_64+0x9f/0x180
  ? lockdep_hardirqs_on+0x78/0x100
  ? do_syscall_64+0x9f/0x180
  entry_SYSCALL_64_after_hwframe+0x76/0x7e
 RIP: 0033:0x7f436712b68b
 RSP: 002b:00007ffe9f1a8658 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
 RAX: ffffffffffffffda RBX: 00005559b367fd80 RCX: 00007f436712b68b
 RDX: 0000000000000000 RSI: 0000000000000800 RDI: 00005559b367fde8
 RBP: 00007ffe9f1a8680 R08: 1999999999999999 R09: 0000000000000000
 R10: 00007f43671a5fe0 R11: 0000000000000206 R12: 0000000000000000
 R13: 00007ffe9f1a86b0 R14: 0000000000000000 R15: 0000000000000000
  </TASK>

Reported-by: Shin'ichiro Kawasaki <[email protected]>
CC: <[email protected]> # 6.13+
Tested-by: Shin'ichiro Kawasaki <[email protected]>
Reviewed-by: Damien Le Moal <[email protected]>
Reviewed-by: Johannes Thumshirn <[email protected]>
Signed-off-by: Naohiro Aota <[email protected]>
Signed-off-by: David Sterba <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
It looks like GPUs are used after shutdown is invoked.
Thus, breaking virtio gpu in the shutdown callback is not a good idea -
guest hangs attempting to finish console drawing, with these warnings:

[   20.504464] WARNING: CPU: 0 PID: 568 at drivers/gpu/drm/virtio/virtgpu_vq.c:358 virtio_gpu_queue_ctrl_sgs+0x236/0x290 [virtio_gpu]
[   20.505685] Modules linked in: nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 rfkill ip_set nf_tables nfnetlink vfat fat intel_rapl_msr intel_rapl_common intel_uncore_frequency_common nfit libnvdimm kvm_intel kvm rapl iTCO_wdt iTCO_vendor_support virtio_gpu virtio_dma_buf pcspkr drm_shmem_helper i2c_i801 drm_kms_helper lpc_ich i2c_smbus virtio_balloon joydev drm fuse xfs libcrc32c ahci libahci crct10dif_pclmul crc32_pclmul crc32c_intel libata virtio_net ghash_clmulni_intel net_failover virtio_blk failover serio_raw dm_mirror dm_region_hash dm_log dm_mod
[   20.511847] CPU: 0 PID: 568 Comm: kworker/0:3 Kdump: loaded Tainted: G        W         -------  ---  5.14.0-578.6675_1757216455.el9.x86_64 #1
[   20.513157] Hardware name: Red Hat KVM/RHEL, BIOS edk2-20241117-3.el9 11/17/2024
[   20.513918] Workqueue: events drm_fb_helper_damage_work [drm_kms_helper]
[   20.514626] RIP: 0010:virtio_gpu_queue_ctrl_sgs+0x236/0x290 [virtio_gpu]
[   20.515332] Code: 00 00 48 85 c0 74 0c 48 8b 78 08 48 89 ee e8 51 50 00 00 65 ff 0d 42 e3 74 3f 0f 85 69 ff ff ff 0f 1f 44 00 00 e9 5f ff ff ff <0f> 0b e9 3f ff ff ff 48 83 3c 24 00 74 0e 49 8b 7f 40 48 85 ff 74
[   20.517272] RSP: 0018:ff34f0a8c0787ad8 EFLAGS: 00010282
[   20.517820] RAX: 00000000fffffffb RBX: 0000000000000000 RCX: 0000000000000820
[   20.518565] RDX: 0000000000000000 RSI: ff34f0a8c0787be0 RDI: ff218bef03a26300
[   20.519308] RBP: ff218bef03a26300 R08: 0000000000000001 R09: ff218bef07224360
[   20.520059] R10: 0000000000008dc0 R11: 0000000000000002 R12: ff218bef02630028
[   20.520806] R13: ff218bef0263fb48 R14: ff218bef00cb8000 R15: ff218bef07224360
[   20.521555] FS:  0000000000000000(0000) GS:ff218bef7ba00000(0000) knlGS:0000000000000000
[   20.522397] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   20.522996] CR2: 000055ac4f7871c0 CR3: 000000010b9f2002 CR4: 0000000000771ef0
[   20.523740] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   20.524477] DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
[   20.525223] PKRU: 55555554
[   20.525515] Call Trace:
[   20.525777]  <TASK>
[   20.526003]  ? show_trace_log_lvl+0x1c4/0x2df
[   20.526464]  ? show_trace_log_lvl+0x1c4/0x2df
[   20.526925]  ? virtio_gpu_queue_fenced_ctrl_buffer+0x82/0x2c0 [virtio_gpu]
[   20.527643]  ? virtio_gpu_queue_ctrl_sgs+0x236/0x290 [virtio_gpu]
[   20.528282]  ? __warn+0x7e/0xd0
[   20.528621]  ? virtio_gpu_queue_ctrl_sgs+0x236/0x290 [virtio_gpu]
[   20.529256]  ? report_bug+0x100/0x140
[   20.529643]  ? handle_bug+0x3c/0x70
[   20.530010]  ? exc_invalid_op+0x14/0x70
[   20.530421]  ? asm_exc_invalid_op+0x16/0x20
[   20.530862]  ? virtio_gpu_queue_ctrl_sgs+0x236/0x290 [virtio_gpu]
[   20.531506]  ? virtio_gpu_queue_ctrl_sgs+0x174/0x290 [virtio_gpu]
[   20.532148]  virtio_gpu_queue_fenced_ctrl_buffer+0x82/0x2c0 [virtio_gpu]
[   20.532843]  virtio_gpu_primary_plane_update+0x3e2/0x460 [virtio_gpu]
[   20.533520]  drm_atomic_helper_commit_planes+0x108/0x320 [drm_kms_helper]
[   20.534233]  drm_atomic_helper_commit_tail+0x45/0x80 [drm_kms_helper]
[   20.534914]  commit_tail+0xd2/0x130 [drm_kms_helper]
[   20.535446]  drm_atomic_helper_commit+0x11b/0x140 [drm_kms_helper]
[   20.536097]  drm_atomic_commit+0xa4/0xe0 [drm]
[   20.536588]  ? __pfx___drm_printfn_info+0x10/0x10 [drm]
[   20.537162]  drm_atomic_helper_dirtyfb+0x192/0x270 [drm_kms_helper]
[   20.537823]  drm_fbdev_shmem_helper_fb_dirty+0x43/0xa0 [drm_shmem_helper]
[   20.538536]  drm_fb_helper_damage_work+0x87/0x160 [drm_kms_helper]
[   20.539188]  process_one_work+0x194/0x380
[   20.539612]  worker_thread+0x2fe/0x410
[   20.540007]  ? __pfx_worker_thread+0x10/0x10
[   20.540456]  kthread+0xdd/0x100
[   20.540791]  ? __pfx_kthread+0x10/0x10
[   20.541190]  ret_from_fork+0x29/0x50
[   20.541566]  </TASK>
[   20.541802] ---[ end trace 0000000000000000 ]---

It looks like the shutdown is called in the middle of console drawing, so
we should either wait for it to finish, or let drm handle the shutdown.

This patch implements this second option:

Add an option for drivers to bypass the common break+reset handling.
As DRM is careful to flush/synchronize outstanding buffers, it looks like
GPU can just have a NOP there.

Reviewed-by: Eric Auger <[email protected]>
Tested-by: Eric Auger <[email protected]>
Fixes: 8bd2fa0 ("virtio: break and reset virtio devices on device_shutdown()")
Cc: Eric Auger <[email protected]>
Cc: Jocelyn Falempe <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Message-Id: <8490dbeb6f79ed039e6c11d121002618972538a3.1744293540.git.mst@redhat.com>
y86-dev pushed a commit that referenced this pull request May 20, 2025
Dave Hansen reports the following crash on a 32-bit system with
CONFIG_HIGHMEM=y and CONFIG_X86_PAE=y:

  > 0xf75fe000 is the mem_map[] entry for the first page >4GB. It
  > obviously wasn't allocated, thus the oops.

  BUG: unable to handle page fault for address: f75fe000
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  *pdpt = 0000000002da2001 *pde = 000000000300c067 *pte = 0000000000000000
  Oops: Oops: 0002 [#1] SMP NOPTI
  CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.15.0-rc1-00288-ge618ee89561b-dirty Rust-for-Linux#311 PREEMPT(undef)
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
  EIP: __free_pages_core+0x3c/0x74
  ...
  Call Trace:
   memblock_free_pages+0x11/0x2c
   memblock_free_all+0x2ce/0x3a0
   mm_core_init+0xf5/0x320
   start_kernel+0x296/0x79c
   i386_start_kernel+0xad/0xb0
   startup_32_smp+0x151/0x154

The mem_map[] is allocated up to the end of ZONE_HIGHMEM which is defined
by max_pfn.

The bug was introduced by this recent commit:

  6faea34 ("arch, mm: streamline HIGHMEM freeing")

Previously, freeing of high memory was also clamped to the end of
ZONE_HIGHMEM but after this change, memblock_free_all() tries to
free memory above the of ZONE_HIGHMEM as well and that causes
access to mem_map[] entries beyond the end of the memory map.

To fix this, discard the memory after max_pfn from memblock on
32-bit systems so that core MM would be aware only of actually
usable memory.

Fixes: 6faea34 ("arch, mm: streamline HIGHMEM freeing")
Reported-by: Dave Hansen <[email protected]>
Tested-by: Arnd Bergmann <[email protected]>
Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Davide Ciminaghi <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Sean Christopherson <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected] # discussion and submission
y86-dev pushed a commit that referenced this pull request May 20, 2025
syzbot reported:

tipc: Node number set to 1055423674
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 3 UID: 0 PID: 6017 Comm: kworker/3:5 Not tainted 6.15.0-rc1-syzkaller-00246-g900241a5cc15 #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: events tipc_net_finalize_work
RIP: 0010:tipc_mon_reinit_self+0x11c/0x210 net/tipc/monitor.c:719
...
RSP: 0018:ffffc9000356fb68 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000003ee87cba
RDX: 0000000000000000 RSI: ffffffff8dbc56a7 RDI: ffff88804c2cc010
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000007
R13: fffffbfff2111097 R14: ffff88804ead8000 R15: ffff88804ead9010
FS:  0000000000000000(0000) GS:ffff888097ab9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f720eb00 CR3: 000000000e182000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 tipc_net_finalize+0x10b/0x180 net/tipc/net.c:140
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
...
RIP: 0010:tipc_mon_reinit_self+0x11c/0x210 net/tipc/monitor.c:719
...
RSP: 0018:ffffc9000356fb68 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000003ee87cba
RDX: 0000000000000000 RSI: ffffffff8dbc56a7 RDI: ffff88804c2cc010
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000007
R13: fffffbfff2111097 R14: ffff88804ead8000 R15: ffff88804ead9010
FS:  0000000000000000(0000) GS:ffff888097ab9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f720eb00 CR3: 000000000e182000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

There is a racing condition between workqueue created when enabling
bearer and another thread created when disabling bearer right after
that as follow:

enabling_bearer                          | disabling_bearer
---------------                          | ----------------
tipc_disc_timeout()                      |
{                                        | bearer_disable()
 ...                                     | {
 schedule_work(&tn->work);               |  tipc_mon_delete()
 ...                                     |  {
}                                        |   ...
                                         |   write_lock_bh(&mon->lock);
                                         |   mon->self = NULL;
                                         |   write_unlock_bh(&mon->lock);
                                         |   ...
                                         |  }
tipc_net_finalize_work()                 | }
{                                        |
 ...                                     |
 tipc_net_finalize()                     |
 {                                       |
  ...                                    |
  tipc_mon_reinit_self()                 |
  {                                      |
   ...                                   |
   write_lock_bh(&mon->lock);            |
   mon->self->addr = tipc_own_addr(net); |
   write_unlock_bh(&mon->lock);          |
   ...                                   |
  }                                      |
  ...                                    |
 }                                       |
 ...                                     |
}                                        |

'mon->self' is set to NULL in disabling_bearer thread and dereferenced
later in enabling_bearer thread.

This commit fixes this issue by validating 'mon->self' before assigning
node address to it.

Reported-by: [email protected]
Fixes: 46cb01e ("tipc: update mon's self addr when node addr generated")
Signed-off-by: Tung Nguyen <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
[BUG]
There is a bug report that a syzbot reproducer can lead to the following
busy inode at unmount time:

  BTRFS info (device loop1): last unmount of filesystem 1680000e-3c1e-4c46-84b6-56bd3909af50
  VFS: Busy inodes after unmount of loop1 (btrfs)
  ------------[ cut here ]------------
  kernel BUG at fs/super.c:650!
  Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
  CPU: 0 UID: 0 PID: 48168 Comm: syz-executor Not tainted 6.15.0-rc2-00471-g119009db2674 Rust-for-Linux#2 PREEMPT(full)
  Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
  RIP: 0010:generic_shutdown_super+0x2e9/0x390 fs/super.c:650
  Call Trace:
   <TASK>
   kill_anon_super+0x3a/0x60 fs/super.c:1237
   btrfs_kill_super+0x3b/0x50 fs/btrfs/super.c:2099
   deactivate_locked_super+0xbe/0x1a0 fs/super.c:473
   deactivate_super fs/super.c:506 [inline]
   deactivate_super+0xe2/0x100 fs/super.c:502
   cleanup_mnt+0x21f/0x440 fs/namespace.c:1435
   task_work_run+0x14d/0x240 kernel/task_work.c:227
   resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
   exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
   exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
   __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
   syscall_exit_to_user_mode+0x269/0x290 kernel/entry/common.c:218
   do_syscall_64+0xd4/0x250 arch/x86/entry/syscall_64.c:100
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   </TASK>

[CAUSE]
When btrfs_alloc_path() failed, btrfs_iget() directly returned without
releasing the inode already allocated by btrfs_iget_locked().

This results the above busy inode and trigger the kernel BUG.

[FIX]
Fix it by calling iget_failed() if btrfs_alloc_path() failed.

If we hit error inside btrfs_read_locked_inode(), it will properly call
iget_failed(), so nothing to worry about.

Although the iget_failed() cleanup inside btrfs_read_locked_inode() is a
break of the normal error handling scheme, let's fix the obvious bug
and backport first, then rework the error handling later.

Reported-by: Penglei Jiang <[email protected]>
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Fixes: 7c855e1 ("btrfs: remove conditional path allocation in btrfs_read_locked_inode()")
CC: [email protected] # 6.13+
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Penglei Jiang <[email protected]>
Signed-off-by: David Sterba <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
A BUG was reported as below when CONFIG_DEBUG_ATOMIC_SLEEP and
try_verify_in_tasklet are enabled.
[  129.444685][  T934] BUG: sleeping function called from invalid context at drivers/md/dm-bufio.c:2421
[  129.444723][  T934] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 934, name: kworker/1:4
[  129.444740][  T934] preempt_count: 201, expected: 0
[  129.444756][  T934] RCU nest depth: 0, expected: 0
[  129.444781][  T934] Preemption disabled at:
[  129.444789][  T934] [<ffffffd816231900>] shrink_work+0x21c/0x248
[  129.445167][  T934] kernel BUG at kernel/sched/walt/walt_debug.c:16!
[  129.445183][  T934] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
[  129.445204][  T934] Skip md ftrace buffer dump for: 0x1609e0
[  129.447348][  T934] CPU: 1 PID: 934 Comm: kworker/1:4 Tainted: G        W  OE      6.6.56-android15-8-o-g6f82312b30b9-debug #1 1400000003000000474e5500b3187743670464e8
[  129.447362][  T934] Hardware name: Qualcomm Technologies, Inc. Parrot QRD, Alpha-M (DT)
[  129.447373][  T934] Workqueue: dm_bufio_cache shrink_work
[  129.447394][  T934] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  129.447406][  T934] pc : android_rvh_schedule_bug+0x0/0x8 [sched_walt_debug]
[  129.447435][  T934] lr : __traceiter_android_rvh_schedule_bug+0x44/0x6c
[  129.447451][  T934] sp : ffffffc0843dbc90
[  129.447459][  T934] x29: ffffffc0843dbc90 x28: ffffffffffffffff x27: 0000000000000c8b
[  129.447479][  T934] x26: 0000000000000040 x25: ffffff804b3d6260 x24: ffffffd816232b68
[  129.447497][  T934] x23: ffffff805171c5b4 x22: 0000000000000000 x21: ffffffd816231900
[  129.447517][  T934] x20: ffffff80306ba898 x19: 0000000000000000 x18: ffffffc084159030
[  129.447535][  T934] x17: 00000000d2b5dd1f x16: 00000000d2b5dd1f x15: ffffffd816720358
[  129.447554][  T934] x14: 0000000000000004 x13: ffffff89ef978000 x12: 0000000000000003
[  129.447572][  T934] x11: ffffffd817a823c4 x10: 0000000000000202 x9 : 7e779c5735de9400
[  129.447591][  T934] x8 : ffffffd81560d004 x7 : 205b5d3938373434 x6 : ffffffd8167397c8
[  129.447610][  T934] x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffffffc0843db9e0
[  129.447629][  T934] x2 : 0000000000002f15 x1 : 0000000000000000 x0 : 0000000000000000
[  129.447647][  T934] Call trace:
[  129.447655][  T934]  android_rvh_schedule_bug+0x0/0x8 [sched_walt_debug 1400000003000000474e550080cce8a8a78606b6]
[  129.447681][  T934]  __might_resched+0x190/0x1a8
[  129.447694][  T934]  shrink_work+0x180/0x248
[  129.447706][  T934]  process_one_work+0x260/0x624
[  129.447718][  T934]  worker_thread+0x28c/0x454
[  129.447729][  T934]  kthread+0x118/0x158
[  129.447742][  T934]  ret_from_fork+0x10/0x20
[  129.447761][  T934] Code: ???????? ???????? ???????? d2b5dd1f (d4210000)
[  129.447772][  T934] ---[ end trace 0000000000000000 ]---

dm_bufio_lock will call spin_lock_bh when try_verify_in_tasklet
is enabled, and __scan will be called in atomic context.

Fixes: 7cd3267 ("dm bufio: remove dm_bufio_cond_resched()")
Signed-off-by: LongPing Wei <[email protected]>
Cc: [email protected]
Signed-off-by: Mikulas Patocka <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
Commit ddd0a42 only increments scomp_scratch_users when it was 0,
causing a panic when using ipcomp:

    Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
    KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
    CPU: 1 UID: 0 PID: 619 Comm: ping Tainted: G                 N  6.15.0-rc3-net-00032-ga79be02bba5c Rust-for-Linux#41 PREEMPT(full)
    Tainted: [N]=TEST
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
    RIP: 0010:inflate_fast+0x5a2/0x1b90
    [...]
    Call Trace:
     <IRQ>
     zlib_inflate+0x2d60/0x6620
     deflate_sdecompress+0x166/0x350
     scomp_acomp_comp_decomp+0x45f/0xa10
     scomp_acomp_decompress+0x21/0x120
     acomp_do_req_chain+0x3e5/0x4e0
     ipcomp_input+0x212/0x550
     xfrm_input+0x2de2/0x72f0
    [...]
    Kernel panic - not syncing: Fatal exception in interrupt
    Kernel Offset: disabled
    ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

Instead, let's keep the old increment, and decrement back to 0 if the
scratch allocation fails.

Fixes: ddd0a42 ("crypto: scompress - Fix scratch allocation failure handling")
Signed-off-by: Sabrina Dubroca <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
For some SPI flash memory operations, dummy bytes are not mandatory. For
example, in Winbond SPINAND flash memory devices, the `write_cache` and
`update_cache` operation variants have zero dummy bytes. Calculating the
duration for SPI memory operations with zero dummy bytes causes
a divide error when `ncycles` is calculated in the
spi_mem_calc_op_duration().

Add changes to skip the 'ncylcles' calculation for zero dummy bytes.

Following divide error is fixed by this change:

 Oops: divide error: 0000 [#1] PREEMPT SMP NOPTI
...

  ? do_trap+0xdb/0x100
  ? do_error_trap+0x75/0xb0
  ? spi_mem_calc_op_duration+0x56/0xb0
  ? exc_divide_error+0x3b/0x70
  ? spi_mem_calc_op_duration+0x56/0xb0
  ? asm_exc_divide_error+0x1b/0x20
  ? spi_mem_calc_op_duration+0x56/0xb0
  ? spinand_select_op_variant+0xee/0x190 [spinand]
  spinand_match_and_init+0x13e/0x1a0 [spinand]
  spinand_manufacturer_match+0x6e/0xa0 [spinand]
  spinand_probe+0x357/0x7f0 [spinand]
  ? kernfs_activate+0x87/0xd0
  spi_mem_probe+0x7a/0xb0
  spi_probe+0x7d/0x130

Fixes: 226d6cb ("spi: spi-mem: Estimate the time taken by operations")
Suggested-by: Krishnamoorthi M <[email protected]>
Co-developed-by: Akshata MukundShetty <[email protected]>
Signed-off-by: Akshata MukundShetty <[email protected]>
Signed-off-by: Raju Rangoju <[email protected]>
Link: https://patch.msgid.link/[email protected]
Reviewed-by: Miquel Raynal <[email protected]>
Signed-off-by: Mark Brown <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
queue->state_change is set as part of nvmet_tcp_set_queue_sock(), but if
the TCP connection isn't established when nvmet_tcp_set_queue_sock() is
called then queue->state_change isn't set and sock->sk->sk_state_change
isn't replaced.

As such we don't need to restore sock->sk->sk_state_change if
queue->state_change is NULL.

This avoids NULL pointer dereferences such as this:

[  286.462026][    C0] BUG: kernel NULL pointer dereference, address: 0000000000000000
[  286.462814][    C0] #PF: supervisor instruction fetch in kernel mode
[  286.463796][    C0] #PF: error_code(0x0010) - not-present page
[  286.464392][    C0] PGD 8000000140620067 P4D 8000000140620067 PUD 114201067 PMD 0
[  286.465086][    C0] Oops: Oops: 0010 [#1] SMP KASAN PTI
[  286.465559][    C0] CPU: 0 UID: 0 PID: 1628 Comm: nvme Not tainted 6.15.0-rc2+ Rust-for-Linux#11 PREEMPT(voluntary)
[  286.466393][    C0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014
[  286.467147][    C0] RIP: 0010:0x0
[  286.467420][    C0] Code: Unable to access opcode bytes at 0xffffffffffffffd6.
[  286.467977][    C0] RSP: 0018:ffff8883ae008580 EFLAGS: 00010246
[  286.468425][    C0] RAX: 0000000000000000 RBX: ffff88813fd34100 RCX: ffffffffa386cc43
[  286.469019][    C0] RDX: 1ffff11027fa68b6 RSI: 0000000000000008 RDI: ffff88813fd34100
[  286.469545][    C0] RBP: ffff88813fd34160 R08: 0000000000000000 R09: ffffed1027fa682c
[  286.470072][    C0] R10: ffff88813fd34167 R11: 0000000000000000 R12: ffff88813fd344c3
[  286.470585][    C0] R13: ffff88813fd34112 R14: ffff88813fd34aec R15: ffff888132cdd268
[  286.471070][    C0] FS:  00007fe3c04c7d80(0000) GS:ffff88840743f000(0000) knlGS:0000000000000000
[  286.471644][    C0] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  286.472543][    C0] CR2: ffffffffffffffd6 CR3: 000000012daca000 CR4: 00000000000006f0
[  286.473500][    C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  286.474467][    C0] DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7: 0000000000000400
[  286.475453][    C0] Call Trace:
[  286.476102][    C0]  <IRQ>
[  286.476719][    C0]  tcp_fin+0x2bb/0x440
[  286.477429][    C0]  tcp_data_queue+0x190f/0x4e60
[  286.478174][    C0]  ? __build_skb_around+0x234/0x330
[  286.478940][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.479659][    C0]  ? __pfx_tcp_data_queue+0x10/0x10
[  286.480431][    C0]  ? tcp_try_undo_loss+0x640/0x6c0
[  286.481196][    C0]  ? seqcount_lockdep_reader_access.constprop.0+0x82/0x90
[  286.482046][    C0]  ? kvm_clock_get_cycles+0x14/0x30
[  286.482769][    C0]  ? ktime_get+0x66/0x150
[  286.483433][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.484146][    C0]  tcp_rcv_established+0x6e4/0x2050
[  286.484857][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.485523][    C0]  ? ipv4_dst_check+0x160/0x2b0
[  286.486203][    C0]  ? __pfx_tcp_rcv_established+0x10/0x10
[  286.486917][    C0]  ? lock_release+0x217/0x2c0
[  286.487595][    C0]  tcp_v4_do_rcv+0x4d6/0x9b0
[  286.488279][    C0]  tcp_v4_rcv+0x2af8/0x3e30
[  286.488904][    C0]  ? raw_local_deliver+0x51b/0xad0
[  286.489551][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.490198][    C0]  ? __pfx_tcp_v4_rcv+0x10/0x10
[  286.490813][    C0]  ? __pfx_raw_local_deliver+0x10/0x10
[  286.491487][    C0]  ? __pfx_nf_confirm+0x10/0x10 [nf_conntrack]
[  286.492275][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.492900][    C0]  ip_protocol_deliver_rcu+0x8f/0x370
[  286.493579][    C0]  ip_local_deliver_finish+0x297/0x420
[  286.494268][    C0]  ip_local_deliver+0x168/0x430
[  286.494867][    C0]  ? __pfx_ip_local_deliver+0x10/0x10
[  286.495498][    C0]  ? __pfx_ip_local_deliver_finish+0x10/0x10
[  286.496204][    C0]  ? ip_rcv_finish_core+0x19a/0x1f20
[  286.496806][    C0]  ? lock_release+0x217/0x2c0
[  286.497414][    C0]  ip_rcv+0x455/0x6e0
[  286.497945][    C0]  ? __pfx_ip_rcv+0x10/0x10
[  286.498550][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.499137][    C0]  ? __pfx_ip_rcv_finish+0x10/0x10
[  286.499763][    C0]  ? lock_release+0x217/0x2c0
[  286.500327][    C0]  ? dl_scaled_delta_exec+0xd1/0x2c0
[  286.500922][    C0]  ? __pfx_ip_rcv+0x10/0x10
[  286.501480][    C0]  __netif_receive_skb_one_core+0x166/0x1b0
[  286.502173][    C0]  ? __pfx___netif_receive_skb_one_core+0x10/0x10
[  286.502903][    C0]  ? lock_acquire+0x2b2/0x310
[  286.503487][    C0]  ? process_backlog+0x372/0x1350
[  286.504087][    C0]  ? lock_release+0x217/0x2c0
[  286.504642][    C0]  process_backlog+0x3b9/0x1350
[  286.505214][    C0]  ? process_backlog+0x372/0x1350
[  286.505779][    C0]  __napi_poll.constprop.0+0xa6/0x490
[  286.506363][    C0]  net_rx_action+0x92e/0xe10
[  286.506889][    C0]  ? __pfx_net_rx_action+0x10/0x10
[  286.507437][    C0]  ? timerqueue_add+0x1f0/0x320
[  286.507977][    C0]  ? sched_clock_cpu+0x68/0x540
[  286.508492][    C0]  ? lock_acquire+0x2b2/0x310
[  286.509043][    C0]  ? kvm_sched_clock_read+0xd/0x20
[  286.509607][    C0]  ? handle_softirqs+0x1aa/0x7d0
[  286.510187][    C0]  handle_softirqs+0x1f2/0x7d0
[  286.510754][    C0]  ? __pfx_handle_softirqs+0x10/0x10
[  286.511348][    C0]  ? irqtime_account_irq+0x181/0x290
[  286.511937][    C0]  ? __dev_queue_xmit+0x85d/0x3450
[  286.512510][    C0]  do_softirq.part.0+0x89/0xc0
[  286.513100][    C0]  </IRQ>
[  286.513548][    C0]  <TASK>
[  286.513953][    C0]  __local_bh_enable_ip+0x112/0x140
[  286.514522][    C0]  ? __dev_queue_xmit+0x85d/0x3450
[  286.515072][    C0]  __dev_queue_xmit+0x872/0x3450
[  286.515619][    C0]  ? nft_do_chain+0xe16/0x15b0 [nf_tables]
[  286.516252][    C0]  ? __pfx___dev_queue_xmit+0x10/0x10
[  286.516817][    C0]  ? selinux_ip_postroute+0x43c/0xc50
[  286.517433][    C0]  ? __pfx_selinux_ip_postroute+0x10/0x10
[  286.518061][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.518606][    C0]  ? ip_output+0x164/0x4a0
[  286.519149][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.519671][    C0]  ? ip_finish_output2+0x17d5/0x1fb0
[  286.520258][    C0]  ip_finish_output2+0xb4b/0x1fb0
[  286.520787][    C0]  ? __pfx_ip_finish_output2+0x10/0x10
[  286.521355][    C0]  ? __ip_finish_output+0x15d/0x750
[  286.521890][    C0]  ip_output+0x164/0x4a0
[  286.522372][    C0]  ? __pfx_ip_output+0x10/0x10
[  286.522872][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.523402][    C0]  ? _raw_spin_unlock_irqrestore+0x4c/0x60
[  286.524031][    C0]  ? __pfx_ip_finish_output+0x10/0x10
[  286.524605][    C0]  ? __ip_queue_xmit+0x999/0x2260
[  286.525200][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.525744][    C0]  ? ipv4_dst_check+0x16a/0x2b0
[  286.526279][    C0]  ? lock_release+0x217/0x2c0
[  286.526793][    C0]  __ip_queue_xmit+0x1883/0x2260
[  286.527324][    C0]  ? __skb_clone+0x54c/0x730
[  286.527827][    C0]  __tcp_transmit_skb+0x209b/0x37a0
[  286.528374][    C0]  ? __pfx___tcp_transmit_skb+0x10/0x10
[  286.528952][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.529472][    C0]  ? seqcount_lockdep_reader_access.constprop.0+0x82/0x90
[  286.530152][    C0]  ? trace_hardirqs_on+0x12/0x120
[  286.530691][    C0]  tcp_write_xmit+0xb81/0x88b0
[  286.531224][    C0]  ? mod_memcg_state+0x4d/0x60
[  286.531736][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.532253][    C0]  __tcp_push_pending_frames+0x90/0x320
[  286.532826][    C0]  tcp_send_fin+0x141/0xb50
[  286.533352][    C0]  ? __pfx_tcp_send_fin+0x10/0x10
[  286.533908][    C0]  ? __local_bh_enable_ip+0xab/0x140
[  286.534495][    C0]  inet_shutdown+0x243/0x320
[  286.535077][    C0]  nvme_tcp_alloc_queue+0xb3b/0x2590 [nvme_tcp]
[  286.535709][    C0]  ? do_raw_spin_lock+0x129/0x260
[  286.536314][    C0]  ? __pfx_nvme_tcp_alloc_queue+0x10/0x10 [nvme_tcp]
[  286.536996][    C0]  ? do_raw_spin_unlock+0x54/0x1e0
[  286.537550][    C0]  ? _raw_spin_unlock+0x29/0x50
[  286.538127][    C0]  ? do_raw_spin_lock+0x129/0x260
[  286.538664][    C0]  ? __pfx_do_raw_spin_lock+0x10/0x10
[  286.539249][    C0]  ? nvme_tcp_alloc_admin_queue+0xd5/0x340 [nvme_tcp]
[  286.539892][    C0]  ? __wake_up+0x40/0x60
[  286.540392][    C0]  nvme_tcp_alloc_admin_queue+0xd5/0x340 [nvme_tcp]
[  286.541047][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.541589][    C0]  nvme_tcp_setup_ctrl+0x8b/0x7a0 [nvme_tcp]
[  286.542254][    C0]  ? _raw_spin_unlock_irqrestore+0x4c/0x60
[  286.542887][    C0]  ? __pfx_nvme_tcp_setup_ctrl+0x10/0x10 [nvme_tcp]
[  286.543568][    C0]  ? trace_hardirqs_on+0x12/0x120
[  286.544166][    C0]  ? _raw_spin_unlock_irqrestore+0x35/0x60
[  286.544792][    C0]  ? nvme_change_ctrl_state+0x196/0x2e0 [nvme_core]
[  286.545477][    C0]  nvme_tcp_create_ctrl+0x839/0xb90 [nvme_tcp]
[  286.546126][    C0]  nvmf_dev_write+0x3db/0x7e0 [nvme_fabrics]
[  286.546775][    C0]  ? rw_verify_area+0x69/0x520
[  286.547334][    C0]  vfs_write+0x218/0xe90
[  286.547854][    C0]  ? do_syscall_64+0x9f/0x190
[  286.548408][    C0]  ? trace_hardirqs_on_prepare+0xdb/0x120
[  286.549037][    C0]  ? syscall_exit_to_user_mode+0x93/0x280
[  286.549659][    C0]  ? __pfx_vfs_write+0x10/0x10
[  286.550259][    C0]  ? do_syscall_64+0x9f/0x190
[  286.550840][    C0]  ? syscall_exit_to_user_mode+0x8e/0x280
[  286.551516][    C0]  ? trace_hardirqs_on_prepare+0xdb/0x120
[  286.552180][    C0]  ? syscall_exit_to_user_mode+0x93/0x280
[  286.552834][    C0]  ? ksys_read+0xf5/0x1c0
[  286.553386][    C0]  ? __pfx_ksys_read+0x10/0x10
[  286.553964][    C0]  ksys_write+0xf5/0x1c0
[  286.554499][    C0]  ? __pfx_ksys_write+0x10/0x10
[  286.555072][    C0]  ? trace_hardirqs_on_prepare+0xdb/0x120
[  286.555698][    C0]  ? syscall_exit_to_user_mode+0x93/0x280
[  286.556319][    C0]  ? do_syscall_64+0x54/0x190
[  286.556866][    C0]  do_syscall_64+0x93/0x190
[  286.557420][    C0]  ? rcu_read_unlock+0x17/0x60
[  286.557986][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.558526][    C0]  ? lock_release+0x217/0x2c0
[  286.559087][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.559659][    C0]  ? count_memcg_events.constprop.0+0x4a/0x60
[  286.560476][    C0]  ? exc_page_fault+0x7a/0x110
[  286.561064][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.561647][    C0]  ? lock_release+0x217/0x2c0
[  286.562257][    C0]  ? do_user_addr_fault+0x171/0xa00
[  286.562839][    C0]  ? do_user_addr_fault+0x4a2/0xa00
[  286.563453][    C0]  ? irqentry_exit_to_user_mode+0x84/0x270
[  286.564112][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.564677][    C0]  ? irqentry_exit_to_user_mode+0x84/0x270
[  286.565317][    C0]  ? trace_hardirqs_on_prepare+0xdb/0x120
[  286.565922][    C0]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  286.566542][    C0] RIP: 0033:0x7fe3c05e6504
[  286.567102][    C0] Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d c5 8b 10 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
[  286.568931][    C0] RSP: 002b:00007fff76444f58 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[  286.569807][    C0] RAX: ffffffffffffffda RBX: 000000003b40d930 RCX: 00007fe3c05e6504
[  286.570621][    C0] RDX: 00000000000000cf RSI: 000000003b40d930 RDI: 0000000000000003
[  286.571443][    C0] RBP: 0000000000000003 R08: 00000000000000cf R09: 000000003b40d930
[  286.572246][    C0] R10: 0000000000000000 R11: 0000000000000202 R12: 000000003b40cd60
[  286.573069][    C0] R13: 00000000000000cf R14: 00007fe3c07417f8 R15: 00007fe3c073502e
[  286.573886][    C0]  </TASK>

Closes: https://lore.kernel.org/linux-nvme/5hdonndzoqa265oq3bj6iarwtfk5dewxxjtbjvn5uqnwclpwt6@a2n6w3taxxex/
Signed-off-by: Alistair Francis <[email protected]>
Reviewed-by: Sagi Grimberg <[email protected]>
Tested-by: Shin'ichiro Kawasaki <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
Use a separate lock in the polling function eu_stall_data_buf_poll()
instead of eu_stall->stream_lock. This would prevent a possible
circular locking dependency leading to a deadlock as described below.
This would also require additional locking with the new lock in
the read function.

<4> [787.192986] ======================================================
<4> [787.192988] WARNING: possible circular locking dependency detected
<4> [787.192991] 6.14.0-rc7-xe+ #1 Tainted: G     U
<4> [787.192993] ------------------------------------------------------
<4> [787.192994] xe_eu_stall/20093 is trying to acquire lock:
<4> [787.192996] ffff88819847e2c0 ((work_completion)
(&(&stream->buf_poll_work)->work)), at: __flush_work+0x1f8/0x5e0
<4> [787.193005] but task is already holding lock:
<4> [787.193007] ffff88814ce83ba8 (&gt->eu_stall->stream_lock){3:3},
at: xe_eu_stall_stream_ioctl+0x41/0x6a0 [xe]
<4> [787.193090] which lock already depends on the new lock.
<4> [787.193093] the existing dependency chain (in reverse order) is:
<4> [787.193095]
-> #1 (&gt->eu_stall->stream_lock){+.+.}-{3:3}:
<4> [787.193099]        __mutex_lock+0xb4/0xe40
<4> [787.193104]        mutex_lock_nested+0x1b/0x30
<4> [787.193106]        eu_stall_data_buf_poll_work_fn+0x44/0x1d0 [xe]
<4> [787.193155]        process_one_work+0x21c/0x740
<4> [787.193159]        worker_thread+0x1db/0x3c0
<4> [787.193161]        kthread+0x10d/0x270
<4> [787.193164]        ret_from_fork+0x44/0x70
<4> [787.193168]        ret_from_fork_asm+0x1a/0x30
<4> [787.193172]
-> #0 ((work_completion)(&(&stream->buf_poll_work)->work)){+.+.}-{0:0}:
<4> [787.193176]        __lock_acquire+0x1637/0x2810
<4> [787.193180]        lock_acquire+0xc9/0x300
<4> [787.193183]        __flush_work+0x219/0x5e0
<4> [787.193186]        cancel_delayed_work_sync+0x87/0x90
<4> [787.193189]        xe_eu_stall_disable_locked+0x9a/0x260 [xe]
<4> [787.193237]        xe_eu_stall_stream_ioctl+0x5b/0x6a0 [xe]
<4> [787.193285]        __x64_sys_ioctl+0xa4/0xe0
<4> [787.193289]        x64_sys_call+0x131e/0x2650
<4> [787.193292]        do_syscall_64+0x91/0x180
<4> [787.193295]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
<4> [787.193299]
other info that might help us debug this:
<4> [787.193302]  Possible unsafe locking scenario:
<4> [787.193304]        CPU0                    CPU1
<4> [787.193305]        ----                    ----
<4> [787.193306]   lock(&gt->eu_stall->stream_lock);
<4> [787.193308]                        lock((work_completion)
					(&(&stream->buf_poll_work)->work));
<4> [787.193311]                        lock(&gt->eu_stall->stream_lock);
<4> [787.193313]   lock((work_completion)
			(&(&stream->buf_poll_work)->work));
<4> [787.193315]
 *** DEADLOCK ***

Fixes: 760edec ("drm/xe/eustall: Add support to read() and poll() EU stall data")
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4598
Signed-off-by: Harish Chegondi <[email protected]>
Reviewed-by: Ashutosh Dixit <[email protected]>
Signed-off-by: Ashutosh Dixit <[email protected]>
Link: https://lore.kernel.org/r/c896932fca84f79db2df5942911997ed77b2b9b6.1744934656.git.harish.chegondi@intel.com
(cherry picked from commit c2b1f1b)
Signed-off-by: Lucas De Marchi <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
Commit a595138 ("arm64: errata: Add newer ARM cores to the
spectre_bhb_loop_affected() lists") added some additional CPUs to the
Spectre-BHB workaround, including some new arrays for designs that
require new 'k' values for the workaround to be effective.

Unfortunately, the new arrays omitted the sentinel entry and so
is_midr_in_range_list() will walk off the end when it doesn't find a
match. With UBSAN enabled, this leads to a crash during boot when
is_midr_in_range_list() is inlined (which was more common prior to
c8c2647 ("arm64: Make  _midr_in_range_list() an exported
function")):

 |  Internal error: aarch64 BRK: 00000000f2000001 [#1] PREEMPT SMP
 |  pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 |  pc : spectre_bhb_loop_affected+0x28/0x30
 |  lr : is_spectre_bhb_affected+0x170/0x190
 | [...]
 |  Call trace:
 |   spectre_bhb_loop_affected+0x28/0x30
 |   update_cpu_capabilities+0xc0/0x184
 |   init_cpu_features+0x188/0x1a4
 |   cpuinfo_store_boot_cpu+0x4c/0x60
 |   smp_prepare_boot_cpu+0x38/0x54
 |   start_kernel+0x8c/0x478
 |   __primary_switched+0xc8/0xd4
 |  Code: 6b09011f 54000061 52801080 d65f03c0 (d4200020)
 |  ---[ end trace 0000000000000000 ]---
 |  Kernel panic - not syncing: aarch64 BRK: Fatal exception

Add the missing sentinel entries.

Cc: Lee Jones <[email protected]>
Cc: James Morse <[email protected]>
Cc: Doug Anderson <[email protected]>
Cc: Shameer Kolothum <[email protected]>
Cc: <[email protected]>
Reported-by: Greg Kroah-Hartman <[email protected]>
Fixes: a595138 ("arm64: errata: Add newer ARM cores to the spectre_bhb_loop_affected() lists")
Signed-off-by: Will Deacon <[email protected]>
Reviewed-by: Lee Jones <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
btrfs_prelim_ref() calls the old and new reference variables in the
incorrect order. This causes a NULL pointer dereference because oldref
is passed as NULL to trace_btrfs_prelim_ref_insert().

Note, trace_btrfs_prelim_ref_insert() is being called with newref as
oldref (and oldref as NULL) on purpose in order to print out
the values of newref.

To reproduce:
echo 1 > /sys/kernel/debug/tracing/events/btrfs/btrfs_prelim_ref_insert/enable

Perform some writeback operations.

Backtrace:
BUG: kernel NULL pointer dereference, address: 0000000000000018
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 115949067 P4D 115949067 PUD 11594a067 PMD 0
 Oops: Oops: 0000 [#1] SMP NOPTI
 CPU: 1 UID: 0 PID: 1188 Comm: fsstress Not tainted 6.15.0-rc2-tester+ Rust-for-Linux#47 PREEMPT(voluntary)  7ca2cef72d5e9c600f0c7718adb6462de8149622
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-2-gc13ff2cd-prebuilt.qemu.org 04/01/2014
 RIP: 0010:trace_event_raw_event_btrfs__prelim_ref+0x72/0x130
 Code: e8 43 81 9f ff 48 85 c0 74 78 4d 85 e4 0f 84 8f 00 00 00 49 8b 94 24 c0 06 00 00 48 8b 0a 48 89 48 08 48 8b 52 08 48 89 50 10 <49> 8b 55 18 48 89 50 18 49 8b 55 20 48 89 50 20 41 0f b6 55 28 88
 RSP: 0018:ffffce44820077a0 EFLAGS: 00010286
 RAX: ffff8c6b403f9014 RBX: ffff8c6b55825730 RCX: 304994edf9cf506b
 RDX: d8b11eb7f0fdb699 RSI: ffff8c6b403f9010 RDI: ffff8c6b403f9010
 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000010
 R10: 00000000ffffffff R11: 0000000000000000 R12: ffff8c6b4e8fb000
 R13: 0000000000000000 R14: ffffce44820077a8 R15: ffff8c6b4abd1540
 FS:  00007f4dc6813740(0000) GS:ffff8c6c1d378000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000018 CR3: 000000010eb42000 CR4: 0000000000750ef0
 PKRU: 55555554
 Call Trace:
  <TASK>
  prelim_ref_insert+0x1c1/0x270
  find_parent_nodes+0x12a6/0x1ee0
  ? __entry_text_end+0x101f06/0x101f09
  ? srso_alias_return_thunk+0x5/0xfbef5
  ? srso_alias_return_thunk+0x5/0xfbef5
  ? srso_alias_return_thunk+0x5/0xfbef5
  ? srso_alias_return_thunk+0x5/0xfbef5
  btrfs_is_data_extent_shared+0x167/0x640
  ? fiemap_process_hole+0xd0/0x2c0
  extent_fiemap+0xa5c/0xbc0
  ? __entry_text_end+0x101f05/0x101f09
  btrfs_fiemap+0x7e/0xd0
  do_vfs_ioctl+0x425/0x9d0
  __x64_sys_ioctl+0x75/0xc0

Signed-off-by: Goldwyn Rodrigues <[email protected]>
Signed-off-by: David Sterba <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
The blammed commit copied to argv the size of the reallocated argv,
instead of the size of the old_argv, thus reading and copying from
past the old_argv allocated memory.

Following BUG_ON was hit:
[    3.038929][    T1] kernel BUG at lib/string_helpers.c:1040!
[    3.039147][    T1] Internal error: Oops - BUG: 00000000f2000800 [#1]  SMP
...
[    3.056489][    T1] Call trace:
[    3.056591][    T1]  __fortify_panic+0x10/0x18 (P)
[    3.056773][    T1]  dm_split_args+0x20c/0x210
[    3.056942][    T1]  dm_table_add_target+0x13c/0x360
[    3.057132][    T1]  table_load+0x110/0x3ac
[    3.057292][    T1]  dm_ctl_ioctl+0x424/0x56c
[    3.057457][    T1]  __arm64_sys_ioctl+0xa8/0xec
[    3.057634][    T1]  invoke_syscall+0x58/0x10c
[    3.057804][    T1]  el0_svc_common+0xa8/0xdc
[    3.057970][    T1]  do_el0_svc+0x1c/0x28
[    3.058123][    T1]  el0_svc+0x50/0xac
[    3.058266][    T1]  el0t_64_sync_handler+0x60/0xc4
[    3.058452][    T1]  el0t_64_sync+0x1b0/0x1b4
[    3.058620][    T1] Code: f800865e a9bf7bfd 910003fd 941f48aa (d4210000)
[    3.058897][    T1] ---[ end trace 0000000000000000 ]---
[    3.059083][    T1] Kernel panic - not syncing: Oops - BUG: Fatal exception

Fix it by copying the size of src, and not the size of dst, as it was.

Fixes: 5a2a6c4 ("dm: always update the array size in realloc_argv on success")
Cc: [email protected]
Signed-off-by: Tudor Ambarus <[email protected]>
Signed-off-by: Mikulas Patocka <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
Calling core::fmt::write() from rust code while FineIBT is enabled
results in a kernel panic:

[ 4614.199779] kernel BUG at arch/x86/kernel/cet.c:132!
[ 4614.205343] Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[ 4614.211781] CPU: 2 UID: 0 PID: 6057 Comm: dmabuf_dump Tainted: G     U     O       6.12.17-android16-0-g6ab38c534a43 #1 9da040f27673ec3945e23b998a0f8bd64c846599
[ 4614.227832] Tainted: [U]=USER, [O]=OOT_MODULE
[ 4614.241247] RIP: 0010:do_kernel_cp_fault+0xea/0xf0
...
[ 4614.398144] RIP: 0010:_RNvXs5_NtNtNtCs3o2tGsuHyou_4core3fmt3num3impyNtB9_7Display3fmt+0x0/0x20
[ 4614.407792] Code: 48 f7 df 48 0f 48 f9 48 89 f2 89 c6 5d e9 18 fd ff ff 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 41 81 ea 14 61 af 2c 74 03 0f 0b 90 <66> 0f 1f 00 55 48 89 e5 48 89 f2 48 8b 3f be 01 00 00 00 5d e9 e7
[ 4614.428775] RSP: 0018:ffffb95acfa4ba68 EFLAGS: 00010246
[ 4614.434609] RAX: 0000000000000000 RBX: 0000000000000010 RCX: 0000000000000000
[ 4614.442587] RDX: 0000000000000007 RSI: ffffb95acfa4ba70 RDI: ffffb95acfa4bc88
[ 4614.450557] RBP: ffffb95acfa4bae0 R08: ffff0a00ffffff05 R09: 0000000000000070
[ 4614.458527] R10: 0000000000000000 R11: ffffffffab67eaf0 R12: ffffb95acfa4bcc8
[ 4614.466493] R13: ffffffffac5d50f0 R14: 0000000000000000 R15: 0000000000000000
[ 4614.474473]  ? __cfi__RNvXs5_NtNtNtCs3o2tGsuHyou_4core3fmt3num3impyNtB9_7Display3fmt+0x10/0x10
[ 4614.484118]  ? _RNvNtCs3o2tGsuHyou_4core3fmt5write+0x1d2/0x250

This happens because core::fmt::write() calls
core::fmt::rt::Argument::fmt(), which currently has CFI disabled:

library/core/src/fmt/rt.rs:
171     // FIXME: Transmuting formatter in new and indirectly branching to/calling
172     // it here is an explicit CFI violation.
173     #[allow(inline_no_sanitize)]
174     #[no_sanitize(cfi, kcfi)]
175     #[inline]
176     pub(super) unsafe fn fmt(&self, f: &mut Formatter<'_>) -> Result {

This causes a Control Protection exception, because FineIBT has sealed
off the original function's endbr64.

This makes rust currently incompatible with FineIBT. Add a Kconfig
dependency that prevents FineIBT from getting turned on by default
if rust is enabled.

[ Rust 1.88.0 (scheduled for 2025-06-26) should have this fixed [1],
  and thus we relaxed the condition with Rust >= 1.88.

  When `objtool` lands checking for this with e.g. [2], the plan is
  to ideally run that in upstream Rust's CI to prevent regressions
  early [3], since we do not control `core`'s source code.

  Alice tested the Rust PR backported to an older compiler.

  Peter would like that Rust provides a stable `core` which can be
  pulled into the kernel: "Relying on that much out of tree code is
  'unfortunate'".

    - Miguel ]

Signed-off-by: Paweł Anikiel <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Link: rust-lang/rust#139632 [1]
Link: https://lore.kernel.org/rust-for-linux/[email protected]/ [2]
Link: rust-lang/rust#139632 (comment) [3]
Link: https://lore.kernel.org/r/[email protected]
Link: https://lore.kernel.org/r/att0-CANiq72kjDM0cKALVy4POEzhfdT4nO7tqz0Pm7xM+3=_0+L1t=A@mail.gmail.com
[ Reduced splat. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
…cess

Add __netif_tx_lock() to ensure that only one packet is being
transmitted at a time to avoid race conditions in the netif_txq
struct and prevent packet data corruption. Failing to do so causes
kernel panic with the following error:

[ 2184.746764] ------------[ cut here ]------------
[ 2184.751412] kernel BUG at lib/dynamic_queue_limits.c:99!
[ 2184.756728] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP

logs: https://gist.github.com/MeghanaMalladiTI/9c7aa5fc3b7fb03f87c74aad487956e9

The lock is acquired before calling emac_xmit_xdp_frame() and released after the
call returns. This ensures that the TX queue is protected from concurrent access
during the transmission of XDP frames.

Fixes: 62aa324 ("net: ti: icssg-prueth: Add XDP support")
Signed-off-by: Meghana Malladi <[email protected]>
Reviewed-by: Jacob Keller <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
When userspace does PR_SET_TAGGED_ADDR_CTRL, but Supm extension is not
available, the kernel crashes:

Oops - illegal instruction [#1]
    [snip]
epc : set_tagged_addr_ctrl+0x112/0x15a
 ra : set_tagged_addr_ctrl+0x74/0x15a
epc : ffffffff80011ace ra : ffffffff80011a30 sp : ffffffc60039be10
    [snip]
status: 0000000200000120 badaddr: 0000000010a79073 cause: 0000000000000002
    set_tagged_addr_ctrl+0x112/0x15a
    __riscv_sys_prctl+0x352/0x73c
    do_trap_ecall_u+0x17c/0x20c
    andle_exception+0x150/0x15c

Fix it by checking if Supm is available.

Fixes: 09d6775 ("riscv: Add support for userspace pointer masking")
Signed-off-by: Nam Cao <[email protected]>
Cc: [email protected]
Reviewed-by: Samuel Holland <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexandre Ghiti <[email protected]>
y86-dev pushed a commit that referenced this pull request May 20, 2025
 into HEAD

KVM/riscv fixes for 6.15, take #1

- Add missing reset of smstateen CSRs
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