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| 1 | +fs,hugetlb: fix NULL pointer dereference in hugetlbs_fill_super |
| 2 | + |
| 3 | +jira LE-1907 |
| 4 | +cve {CVE-2024-0841 |
| 5 | +cve RHEL-20617] |
| 6 | +cve [RHEL-20615 |
| 7 | +cve Mitchell) |
| 8 | +cve (Audra |
| 9 | +cve CVE-2024-0841 |
| 10 | +Rebuild_History Non-Buildable kernel-5.14.0-427.16.1.el9_4 |
| 11 | +Rebuild_CHGLOG: - fs,hugetlb: fix NULL pointer dereference in hugetlbs_fill_super {CVE-2024-0841} (Audra Mitchell) [RHEL-20615 RHEL-20617] {CVE-2024-0841} |
| 12 | +Rebuild_FUZZ: 88.73% |
| 13 | +commit-author Oscar Salvador < [email protected]> |
| 14 | +commit 79d72c68c58784a3e1cd2378669d51bfd0cb7498 |
| 15 | +Empty-Commit: Cherry-Pick Conflicts during history rebuild. |
| 16 | +Will be included in final tarball splat. Ref for failed cherry-pick at: |
| 17 | +ciq/ciq_backports/kernel-5.14.0-427.16.1.el9_4/79d72c68.failed |
| 18 | + |
| 19 | +When configuring a hugetlb filesystem via the fsconfig() syscall, there is |
| 20 | +a possible NULL dereference in hugetlbfs_fill_super() caused by assigning |
| 21 | +NULL to ctx->hstate in hugetlbfs_parse_param() when the requested pagesize |
| 22 | +is non valid. |
| 23 | + |
| 24 | +E.g: Taking the following steps: |
| 25 | + |
| 26 | + fd = fsopen("hugetlbfs", FSOPEN_CLOEXEC); |
| 27 | + fsconfig(fd, FSCONFIG_SET_STRING, "pagesize", "1024", 0); |
| 28 | + fsconfig(fd, FSCONFIG_CMD_CREATE, NULL, NULL, 0); |
| 29 | + |
| 30 | +Given that the requested "pagesize" is invalid, ctxt->hstate will be replaced |
| 31 | +with NULL, losing its previous value, and we will print an error: |
| 32 | + |
| 33 | + ... |
| 34 | + ... |
| 35 | + case Opt_pagesize: |
| 36 | + ps = memparse(param->string, &rest); |
| 37 | + ctx->hstate = h; |
| 38 | + if (!ctx->hstate) { |
| 39 | + pr_err("Unsupported page size %lu MB\n", ps / SZ_1M); |
| 40 | + return -EINVAL; |
| 41 | + } |
| 42 | + return 0; |
| 43 | + ... |
| 44 | + ... |
| 45 | + |
| 46 | +This is a problem because later on, we will dereference ctxt->hstate in |
| 47 | +hugetlbfs_fill_super() |
| 48 | + |
| 49 | + ... |
| 50 | + ... |
| 51 | + sb->s_blocksize = huge_page_size(ctx->hstate); |
| 52 | + ... |
| 53 | + ... |
| 54 | + |
| 55 | +Causing below Oops. |
| 56 | + |
| 57 | +Fix this by replacing cxt->hstate value only when then pagesize is known |
| 58 | +to be valid. |
| 59 | + |
| 60 | + kernel: hugetlbfs: Unsupported page size 0 MB |
| 61 | + kernel: BUG: kernel NULL pointer dereference, address: 0000000000000028 |
| 62 | + kernel: #PF: supervisor read access in kernel mode |
| 63 | + kernel: #PF: error_code(0x0000) - not-present page |
| 64 | + kernel: PGD 800000010f66c067 P4D 800000010f66c067 PUD 1b22f8067 PMD 0 |
| 65 | + kernel: Oops: 0000 [#1] PREEMPT SMP PTI |
| 66 | + kernel: CPU: 4 PID: 5659 Comm: syscall Tainted: G E 6.8.0-rc2-default+ #22 5a47c3fef76212addcc6eb71344aabc35190ae8f |
| 67 | + kernel: Hardware name: Intel Corp. GROVEPORT/GROVEPORT, BIOS GVPRCRB1.86B.0016.D04.1705030402 05/03/2017 |
| 68 | + kernel: RIP: 0010:hugetlbfs_fill_super+0xb4/0x1a0 |
| 69 | + kernel: Code: 48 8b 3b e8 3e c6 ed ff 48 85 c0 48 89 45 20 0f 84 d6 00 00 00 48 b8 ff ff ff ff ff ff ff 7f 4c 89 e7 49 89 44 24 20 48 8b 03 <8b> 48 28 b8 00 10 00 00 48 d3 e0 49 89 44 24 18 48 8b 03 8b 40 28 |
| 70 | + kernel: RSP: 0018:ffffbe9960fcbd48 EFLAGS: 00010246 |
| 71 | + kernel: RAX: 0000000000000000 RBX: ffff9af5272ae780 RCX: 0000000000372004 |
| 72 | + kernel: RDX: ffffffffffffffff RSI: ffffffffffffffff RDI: ffff9af555e9b000 |
| 73 | + kernel: RBP: ffff9af52ee66b00 R08: 0000000000000040 R09: 0000000000370004 |
| 74 | + kernel: R10: ffffbe9960fcbd48 R11: 0000000000000040 R12: ffff9af555e9b000 |
| 75 | + kernel: R13: ffffffffa66b86c0 R14: ffff9af507d2f400 R15: ffff9af507d2f400 |
| 76 | + kernel: FS: 00007ffbc0ba4740(0000) GS:ffff9b0bd7000000(0000) knlGS:0000000000000000 |
| 77 | + kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |
| 78 | + kernel: CR2: 0000000000000028 CR3: 00000001b1ee0000 CR4: 00000000001506f0 |
| 79 | + kernel: Call Trace: |
| 80 | + kernel: <TASK> |
| 81 | + kernel: ? __die_body+0x1a/0x60 |
| 82 | + kernel: ? page_fault_oops+0x16f/0x4a0 |
| 83 | + kernel: ? search_bpf_extables+0x65/0x70 |
| 84 | + kernel: ? fixup_exception+0x22/0x310 |
| 85 | + kernel: ? exc_page_fault+0x69/0x150 |
| 86 | + kernel: ? asm_exc_page_fault+0x22/0x30 |
| 87 | + kernel: ? __pfx_hugetlbfs_fill_super+0x10/0x10 |
| 88 | + kernel: ? hugetlbfs_fill_super+0xb4/0x1a0 |
| 89 | + kernel: ? hugetlbfs_fill_super+0x28/0x1a0 |
| 90 | + kernel: ? __pfx_hugetlbfs_fill_super+0x10/0x10 |
| 91 | + kernel: vfs_get_super+0x40/0xa0 |
| 92 | + kernel: ? __pfx_bpf_lsm_capable+0x10/0x10 |
| 93 | + kernel: vfs_get_tree+0x25/0xd0 |
| 94 | + kernel: vfs_cmd_create+0x64/0xe0 |
| 95 | + kernel: __x64_sys_fsconfig+0x395/0x410 |
| 96 | + kernel: do_syscall_64+0x80/0x160 |
| 97 | + kernel: ? syscall_exit_to_user_mode+0x82/0x240 |
| 98 | + kernel: ? do_syscall_64+0x8d/0x160 |
| 99 | + kernel: ? syscall_exit_to_user_mode+0x82/0x240 |
| 100 | + kernel: ? do_syscall_64+0x8d/0x160 |
| 101 | + kernel: ? exc_page_fault+0x69/0x150 |
| 102 | + kernel: entry_SYSCALL_64_after_hwframe+0x6e/0x76 |
| 103 | + kernel: RIP: 0033:0x7ffbc0cb87c9 |
| 104 | + kernel: Code: 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 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 97 96 0d 00 f7 d8 64 89 01 48 |
| 105 | + kernel: RSP: 002b:00007ffc29d2f388 EFLAGS: 00000206 ORIG_RAX: 00000000000001af |
| 106 | + kernel: RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ffbc0cb87c9 |
| 107 | + kernel: RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000003 |
| 108 | + kernel: RBP: 00007ffc29d2f3b0 R08: 0000000000000000 R09: 0000000000000000 |
| 109 | + kernel: R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 |
| 110 | + kernel: R13: 00007ffc29d2f4c0 R14: 0000000000000000 R15: 0000000000000000 |
| 111 | + kernel: </TASK> |
| 112 | + kernel: Modules linked in: rpcsec_gss_krb5(E) auth_rpcgss(E) nfsv4(E) dns_resolver(E) nfs(E) lockd(E) grace(E) sunrpc(E) netfs(E) af_packet(E) bridge(E) stp(E) llc(E) iscsi_ibft(E) iscsi_boot_sysfs(E) intel_rapl_msr(E) intel_rapl_common(E) iTCO_wdt(E) intel_pmc_bxt(E) sb_edac(E) iTCO_vendor_support(E) x86_pkg_temp_thermal(E) intel_powerclamp(E) coretemp(E) kvm_intel(E) rfkill(E) ipmi_ssif(E) kvm(E) acpi_ipmi(E) irqbypass(E) pcspkr(E) igb(E) ipmi_si(E) mei_me(E) i2c_i801(E) joydev(E) intel_pch_thermal(E) i2c_smbus(E) dca(E) lpc_ich(E) mei(E) ipmi_devintf(E) ipmi_msghandler(E) acpi_pad(E) tiny_power_button(E) button(E) fuse(E) efi_pstore(E) configfs(E) ip_tables(E) x_tables(E) ext4(E) mbcache(E) jbd2(E) hid_generic(E) usbhid(E) sd_mod(E) t10_pi(E) crct10dif_pclmul(E) crc32_pclmul(E) crc32c_intel(E) polyval_clmulni(E) ahci(E) xhci_pci(E) polyval_generic(E) gf128mul(E) ghash_clmulni_intel(E) sha512_ssse3(E) sha256_ssse3(E) xhci_pci_renesas(E) libahci(E) ehci_pci(E) sha1_ssse3(E) xhci_hcd(E) ehci_hcd(E) libata(E) |
| 113 | + kernel: mgag200(E) i2c_algo_bit(E) usbcore(E) wmi(E) sg(E) dm_multipath(E) dm_mod(E) scsi_dh_rdac(E) scsi_dh_emc(E) scsi_dh_alua(E) scsi_mod(E) scsi_common(E) aesni_intel(E) crypto_simd(E) cryptd(E) |
| 114 | + kernel: Unloaded tainted modules: acpi_cpufreq(E):1 fjes(E):1 |
| 115 | + kernel: CR2: 0000000000000028 |
| 116 | + kernel: ---[ end trace 0000000000000000 ]--- |
| 117 | + kernel: RIP: 0010:hugetlbfs_fill_super+0xb4/0x1a0 |
| 118 | + kernel: Code: 48 8b 3b e8 3e c6 ed ff 48 85 c0 48 89 45 20 0f 84 d6 00 00 00 48 b8 ff ff ff ff ff ff ff 7f 4c 89 e7 49 89 44 24 20 48 8b 03 <8b> 48 28 b8 00 10 00 00 48 d3 e0 49 89 44 24 18 48 8b 03 8b 40 28 |
| 119 | + kernel: RSP: 0018:ffffbe9960fcbd48 EFLAGS: 00010246 |
| 120 | + kernel: RAX: 0000000000000000 RBX: ffff9af5272ae780 RCX: 0000000000372004 |
| 121 | + kernel: RDX: ffffffffffffffff RSI: ffffffffffffffff RDI: ffff9af555e9b000 |
| 122 | + kernel: RBP: ffff9af52ee66b00 R08: 0000000000000040 R09: 0000000000370004 |
| 123 | + kernel: R10: ffffbe9960fcbd48 R11: 0000000000000040 R12: ffff9af555e9b000 |
| 124 | + kernel: R13: ffffffffa66b86c0 R14: ffff9af507d2f400 R15: ffff9af507d2f400 |
| 125 | + kernel: FS: 00007ffbc0ba4740(0000) GS:ffff9b0bd7000000(0000) knlGS:0000000000000000 |
| 126 | + kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |
| 127 | + kernel: CR2: 0000000000000028 CR3: 00000001b1ee0000 CR4: 00000000001506f0 |
| 128 | + |
| 129 | +Link: https://lkml.kernel.org/r/ [email protected] |
| 130 | +Fixes: 32021982a324 ("hugetlbfs: Convert to fs_context") |
| 131 | + Signed-off-by: Michal Hocko < [email protected]> |
| 132 | + Signed-off-by: Oscar Salvador < [email protected]> |
| 133 | + Acked-by: Muchun Song < [email protected]> |
| 134 | + |
| 135 | + Signed-off-by: Andrew Morton < [email protected]> |
| 136 | +(cherry picked from commit 79d72c68c58784a3e1cd2378669d51bfd0cb7498) |
| 137 | + Signed-off-by: Jonathan Maple < [email protected]> |
| 138 | + |
| 139 | +# Conflicts: |
| 140 | +# fs/hugetlbfs/inode.c |
| 141 | +diff --cc fs/hugetlbfs/inode.c |
| 142 | +index 30f9f68a002e,d746866ae3b6..000000000000 |
| 143 | +--- a/fs/hugetlbfs/inode.c |
| 144 | ++++ b/fs/hugetlbfs/inode.c |
| 145 | +@@@ -1357,11 -1410,12 +1358,18 @@@ static int hugetlbfs_parse_param(struc |
| 146 | + |
| 147 | + case Opt_pagesize: |
| 148 | + ps = memparse(param->string, &rest); |
| 149 | +++<<<<<<< HEAD |
| 150 | + + ctx->hstate = size_to_hstate(ps); |
| 151 | + + if (!ctx->hstate) { |
| 152 | + + pr_err("Unsupported page size %lu MB\n", ps >> 20); |
| 153 | +++======= |
| 154 | ++ h = size_to_hstate(ps); |
| 155 | ++ if (!h) { |
| 156 | ++ pr_err("Unsupported page size %lu MB\n", ps / SZ_1M); |
| 157 | +++>>>>>>> 79d72c68c587 (fs,hugetlb: fix NULL pointer dereference in hugetlbs_fill_super) |
| 158 | + return -EINVAL; |
| 159 | + } |
| 160 | ++ ctx->hstate = h; |
| 161 | + return 0; |
| 162 | + |
| 163 | + case Opt_min_size: |
| 164 | +* Unmerged path fs/hugetlbfs/inode.c |
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