Skip to content

Commit 345fdc3

Browse files
PlaidCatPlaidCat
committed
fork: defer linking file vma until vma is fully initialized
jira LE-1907 cve CVE-2024-27022 Rebuild_History Non-Buildable kernel-5.14.0-427.37.1.el9_4 commit-author Miaohe Lin <[email protected]> commit 35e3517 Empty-Commit: Cherry-Pick Conflicts during history rebuild. Will be included in final tarball splat. Ref for failed cherry-pick at: ciq/ciq_backports/kernel-5.14.0-427.37.1.el9_4/35e35178.failed Thorvald reported a WARNING [1]. And the root cause is below race: CPU 1 CPU 2 fork hugetlbfs_fallocate dup_mmap hugetlbfs_punch_hole i_mmap_lock_write(mapping); vma_interval_tree_insert_after -- Child vma is visible through i_mmap tree. i_mmap_unlock_write(mapping); hugetlb_dup_vma_private -- Clear vma_lock outside i_mmap_rwsem! i_mmap_lock_write(mapping); hugetlb_vmdelete_list vma_interval_tree_foreach hugetlb_vma_trylock_write -- Vma_lock is cleared. tmp->vm_ops->open -- Alloc new vma_lock outside i_mmap_rwsem! hugetlb_vma_unlock_write -- Vma_lock is assigned!!! i_mmap_unlock_write(mapping); hugetlb_dup_vma_private() and hugetlb_vm_op_open() are called outside i_mmap_rwsem lock while vma lock can be used in the same time. Fix this by deferring linking file vma until vma is fully initialized. Those vmas should be initialized first before they can be used. Link: https://lkml.kernel.org/r/[email protected] Fixes: 8d9bfb2 ("hugetlb: add vma based lock for pmd sharing") Signed-off-by: Miaohe Lin <[email protected]> Reported-by: Thorvald Natvig <[email protected]> Closes: https://lore.kernel.org/linux-mm/20240129161735.6gmjsswx62o4pbja@revolver/T/ [1] Reviewed-by: Jane Chu <[email protected]> Cc: Christian Brauner <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Kent Overstreet <[email protected]> Cc: Liam R. Howlett <[email protected]> Cc: Mateusz Guzik <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Miaohe Lin <[email protected]> Cc: Muchun Song <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Peng Zhang <[email protected]> Cc: Tycho Andersen <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> (cherry picked from commit 35e3517) Signed-off-by: Jonathan Maple <[email protected]> # Conflicts: # kernel/fork.c
1 parent 203003f commit 345fdc3

File tree

1 file changed

+135
-0
lines changed

1 file changed

+135
-0
lines changed

‎ciq/ciq_backports/kernel-5.14.0-427.37.1.el9_4/35e35178.failed‎

Lines changed: 135 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,135 @@
1+
fork: defer linking file vma until vma is fully initialized
2+
3+
jira LE-1907
4+
cve CVE-2024-27022
5+
Rebuild_History Non-Buildable kernel-5.14.0-427.37.1.el9_4
6+
commit-author Miaohe Lin <[email protected]>
7+
commit 35e351780fa9d8240dd6f7e4f245f9ea37e96c19
8+
Empty-Commit: Cherry-Pick Conflicts during history rebuild.
9+
Will be included in final tarball splat. Ref for failed cherry-pick at:
10+
ciq/ciq_backports/kernel-5.14.0-427.37.1.el9_4/35e35178.failed
11+
12+
Thorvald reported a WARNING [1]. And the root cause is below race:
13+
14+
CPU 1 CPU 2
15+
fork hugetlbfs_fallocate
16+
dup_mmap hugetlbfs_punch_hole
17+
i_mmap_lock_write(mapping);
18+
vma_interval_tree_insert_after -- Child vma is visible through i_mmap tree.
19+
i_mmap_unlock_write(mapping);
20+
hugetlb_dup_vma_private -- Clear vma_lock outside i_mmap_rwsem!
21+
i_mmap_lock_write(mapping);
22+
hugetlb_vmdelete_list
23+
vma_interval_tree_foreach
24+
hugetlb_vma_trylock_write -- Vma_lock is cleared.
25+
tmp->vm_ops->open -- Alloc new vma_lock outside i_mmap_rwsem!
26+
hugetlb_vma_unlock_write -- Vma_lock is assigned!!!
27+
i_mmap_unlock_write(mapping);
28+
29+
hugetlb_dup_vma_private() and hugetlb_vm_op_open() are called outside
30+
i_mmap_rwsem lock while vma lock can be used in the same time. Fix this
31+
by deferring linking file vma until vma is fully initialized. Those vmas
32+
should be initialized first before they can be used.
33+
34+
Link: https://lkml.kernel.org/r/[email protected]
35+
Fixes: 8d9bfb260814 ("hugetlb: add vma based lock for pmd sharing")
36+
Signed-off-by: Miaohe Lin <[email protected]>
37+
Reported-by: Thorvald Natvig <[email protected]>
38+
Closes: https://lore.kernel.org/linux-mm/20240129161735.6gmjsswx62o4pbja@revolver/T/ [1]
39+
Reviewed-by: Jane Chu <[email protected]>
40+
Cc: Christian Brauner <[email protected]>
41+
Cc: Heiko Carstens <[email protected]>
42+
Cc: Kent Overstreet <[email protected]>
43+
Cc: Liam R. Howlett <[email protected]>
44+
Cc: Mateusz Guzik <[email protected]>
45+
Cc: Matthew Wilcox (Oracle) <[email protected]>
46+
Cc: Miaohe Lin <[email protected]>
47+
Cc: Muchun Song <[email protected]>
48+
Cc: Oleg Nesterov <[email protected]>
49+
Cc: Peng Zhang <[email protected]>
50+
Cc: Tycho Andersen <[email protected]>
51+
Cc: <[email protected]>
52+
Signed-off-by: Andrew Morton <[email protected]>
53+
(cherry picked from commit 35e351780fa9d8240dd6f7e4f245f9ea37e96c19)
54+
Signed-off-by: Jonathan Maple <[email protected]>
55+
56+
# Conflicts:
57+
# kernel/fork.c
58+
diff --cc kernel/fork.c
59+
index a97c37970134,aebb3e6c96dc..000000000000
60+
--- a/kernel/fork.c
61+
+++ b/kernel/fork.c
62+
@@@ -662,7 -713,24 +662,28 @@@ static __latent_entropy int dup_mmap(st
63+
tmp->anon_vma = NULL;
64+
} else if (anon_vma_fork(tmp, mpnt))
65+
goto fail_nomem_anon_vma_fork;
66+
++<<<<<<< HEAD
67+
+ tmp->vm_flags &= ~(VM_LOCKED | VM_LOCKONFAULT);
68+
++=======
69+
+ vm_flags_clear(tmp, VM_LOCKED_MASK);
70+
+ /*
71+
+ * Copy/update hugetlb private vma information.
72+
+ */
73+
+ if (is_vm_hugetlb_page(tmp))
74+
+ hugetlb_dup_vma_private(tmp);
75+
+
76+
+ /*
77+
+ * Link the vma into the MT. After using __mt_dup(), memory
78+
+ * allocation is not necessary here, so it cannot fail.
79+
+ */
80+
+ vma_iter_bulk_store(&vmi, tmp);
81+
+
82+
+ mm->map_count++;
83+
+
84+
+ if (tmp->vm_ops && tmp->vm_ops->open)
85+
+ tmp->vm_ops->open(tmp);
86+
+
87+
++>>>>>>> 35e351780fa9 (fork: defer linking file vma until vma is fully initialized)
88+
file = tmp->vm_file;
89+
if (file) {
90+
struct address_space *mapping = file->f_mapping;
91+
@@@ -679,33 -747,13 +700,43 @@@
92+
i_mmap_unlock_write(mapping);
93+
}
94+
95+
++<<<<<<< HEAD
96+
+ /*
97+
+ * Copy/update hugetlb private vma information.
98+
+ */
99+
+ if (is_vm_hugetlb_page(tmp))
100+
+ hugetlb_dup_vma_private(tmp);
101+
+
102+
+ /*
103+
+ * Link in the new vma and copy the page table entries.
104+
+ */
105+
+ *pprev = tmp;
106+
+ pprev = &tmp->vm_next;
107+
+ tmp->vm_prev = prev;
108+
+ prev = tmp;
109+
+
110+
+ __vma_link_rb(mm, tmp, rb_link, rb_parent);
111+
+ rb_link = &tmp->vm_rb.rb_right;
112+
+ rb_parent = &tmp->vm_rb;
113+
+
114+
+ mm->map_count++;
115+
+ if (!(tmp->vm_flags & VM_WIPEONFORK))
116+
+ retval = copy_page_range(tmp, mpnt);
117+
+
118+
+ if (tmp->vm_ops && tmp->vm_ops->open)
119+
+ tmp->vm_ops->open(tmp);
120+
+
121+
+ if (retval)
122+
+ goto out;
123+
++=======
124+
+ if (!(tmp->vm_flags & VM_WIPEONFORK))
125+
+ retval = copy_page_range(tmp, mpnt);
126+
+
127+
+ if (retval) {
128+
+ mpnt = vma_next(&vmi);
129+
+ goto loop_out;
130+
+ }
131+
++>>>>>>> 35e351780fa9 (fork: defer linking file vma until vma is fully initialized)
132+
}
133+
/* a new mm has just been created */
134+
retval = arch_dup_mmap(oldmm, mm);
135+
* Unmerged path kernel/fork.c

0 commit comments

Comments
 (0)