CVE-2026-74351 (GCVE-0-2026-74351)
Vulnerability from cvelistv5
Published
2026-08-15 05:58
Modified
2026-08-17 05:17
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: rebase copied fsdlm LVB pointers in locking_state
The locking_state debugfs iterator snapshots struct ocfs2_lock_res by
value under ocfs2_dlm_tracking_lock and later formats that copy in
ocfs2_dlm_seq_show(). That is fine for the inline fields, but the
userspace fsdlm stack stores the LVB through lksb_fsdlm.sb_lvbptr. Once
the iterator drops the tracking lock, a copied non-NULL sb_lvbptr still
points into the original lockres owner, so teardown can free that
container before the debugfs dump walks the raw LVB bytes.
Rebase the copied sb_lvbptr to the copied l_lksb before dumping the raw
LVB. The seq snapshot already carries the inline LVB storage reserved in
struct ocfs2_dlm_lksb, so the debugfs reader can dump the copied bytes
without borrowing the original lockres lifetime.
The buggy scenario involves two paths, with each column showing the order
within that path:
locking_state reader: lockres teardown:
1. ocfs2_dlm_seq_start()/next() 1. file release or another owner
copies struct ocfs2_lock_res teardown reaches
2. ocfs2_dlm_seq_show() formats ocfs2_lock_res_free()
the copied row 2. the lockres is removed from the
3. ocfs2_dlm_lvb() follows the tracking list
copied sb_lvbptr 3. the owner frees the original
lockres container
Validation reproduced this kernel report:
KASAN slab-use-after-free in ocfs2_dlm_seq_show+0x1bd/0x430
RIP: 0033:0x7f8ec4b1e29d
The buggy address belongs to the object at ffff88810a1e0800 which belongs
to the cache kmalloc-1k of size 1024
The buggy address is located 368 bytes inside of freed 1024-byte region
[ffff88810a1e0800, ffff88810a1e0c00)
Read of size 1
Call trace:
dump_stack_lvl+0x66/0xa0
print_report+0xce/0x630
ocfs2_dlm_seq_show+0x1bd/0x430 (fs/ocfs2/dlmglue.c:3137)
srso_alias_return_thunk+0x5/0xfbef5
__virt_addr_valid+0x19f/0x330
kasan_report+0xe0/0x110
seq_read_iter+0x29d/0x790
seq_read+0x20a/0x280
find_held_lock+0x2b/0x80
rcu_read_unlock+0x18/0x70
full_proxy_read+0x9e/0xd0
vfs_read+0x12c/0x590
ksys_read+0xd2/0x170
do_user_addr_fault+0x65a/0x890
do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Allocated by task stack:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_kmalloc+0xaa/0xb0
ocfs2_file_open+0x13e/0x300
do_dentry_open+0x233/0x7f0
vfs_open+0x5a/0x1b0
path_openat+0x66d/0x1540
do_file_open+0x186/0x2b0
do_sys_openat2+0xce/0x150
__x64_sys_openat+0xd0/0x140
do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task stack:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x5f/0x80
kfree+0x313/0x590
ocfs2_file_release+0x138/0x260
__fput+0x1df/0x4b0
fput_close_sync+0xd2/0x170
__x64_sys_close+0x55/0x90
do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)
entry_SYSCALL_64_after_hwframe+0x77/0x7f
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: cf4d8d75d8aba537a19b313a9364fd08ddbd5622 Version: cf4d8d75d8aba537a19b313a9364fd08ddbd5622 Version: cf4d8d75d8aba537a19b313a9364fd08ddbd5622 Version: cf4d8d75d8aba537a19b313a9364fd08ddbd5622 Version: cf4d8d75d8aba537a19b313a9364fd08ddbd5622 Version: cf4d8d75d8aba537a19b313a9364fd08ddbd5622 Version: cf4d8d75d8aba537a19b313a9364fd08ddbd5622 Version: cf4d8d75d8aba537a19b313a9364fd08ddbd5622 |
||
{
"containers": {
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"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/ocfs2/dlmglue.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
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"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
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"version": "2.6.26"
},
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"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.261",
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},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
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},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
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"vulnerable": true
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{
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{
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}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: rebase copied fsdlm LVB pointers in locking_state\n\nThe locking_state debugfs iterator snapshots struct ocfs2_lock_res by\nvalue under ocfs2_dlm_tracking_lock and later formats that copy in\nocfs2_dlm_seq_show(). That is fine for the inline fields, but the\nuserspace fsdlm stack stores the LVB through lksb_fsdlm.sb_lvbptr. Once\nthe iterator drops the tracking lock, a copied non-NULL sb_lvbptr still\npoints into the original lockres owner, so teardown can free that\ncontainer before the debugfs dump walks the raw LVB bytes.\n\nRebase the copied sb_lvbptr to the copied l_lksb before dumping the raw\nLVB. The seq snapshot already carries the inline LVB storage reserved in\nstruct ocfs2_dlm_lksb, so the debugfs reader can dump the copied bytes\nwithout borrowing the original lockres lifetime.\n\nThe buggy scenario involves two paths, with each column showing the order\nwithin that path:\n\nlocking_state reader: lockres teardown:\n1. ocfs2_dlm_seq_start()/next() 1. file release or another owner\n copies struct ocfs2_lock_res teardown reaches\n2. ocfs2_dlm_seq_show() formats ocfs2_lock_res_free()\n the copied row 2. the lockres is removed from the\n3. ocfs2_dlm_lvb() follows the tracking list\n copied sb_lvbptr 3. the owner frees the original\n lockres container\n\nValidation reproduced this kernel report:\nKASAN slab-use-after-free in ocfs2_dlm_seq_show+0x1bd/0x430\nRIP: 0033:0x7f8ec4b1e29d\nThe buggy address belongs to the object at ffff88810a1e0800 which belongs\nto the cache kmalloc-1k of size 1024\nThe buggy address is located 368 bytes inside of freed 1024-byte region\n[ffff88810a1e0800, ffff88810a1e0c00)\nRead of size 1\nCall trace:\n dump_stack_lvl+0x66/0xa0\n print_report+0xce/0x630\n ocfs2_dlm_seq_show+0x1bd/0x430 (fs/ocfs2/dlmglue.c:3137)\n srso_alias_return_thunk+0x5/0xfbef5\n __virt_addr_valid+0x19f/0x330\n kasan_report+0xe0/0x110\n seq_read_iter+0x29d/0x790\n seq_read+0x20a/0x280\n find_held_lock+0x2b/0x80\n rcu_read_unlock+0x18/0x70\n full_proxy_read+0x9e/0xd0\n vfs_read+0x12c/0x590\n ksys_read+0xd2/0x170\n do_user_addr_fault+0x65a/0x890\n do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nAllocated by task stack:\n kasan_save_stack+0x33/0x60\n kasan_save_track+0x14/0x30\n __kasan_kmalloc+0xaa/0xb0\n ocfs2_file_open+0x13e/0x300\n do_dentry_open+0x233/0x7f0\n vfs_open+0x5a/0x1b0\n path_openat+0x66d/0x1540\n do_file_open+0x186/0x2b0\n do_sys_openat2+0xce/0x150\n __x64_sys_openat+0xd0/0x140\n do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nFreed by task stack:\n kasan_save_stack+0x33/0x60\n kasan_save_track+0x14/0x30\n kasan_save_free_info+0x3b/0x60\n __kasan_slab_free+0x5f/0x80\n kfree+0x313/0x590\n ocfs2_file_release+0x138/0x260\n __fput+0x1df/0x4b0\n fput_close_sync+0xd2/0x170\n __x64_sys_close+0x55/0x90\n do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)\n entry_SYSCALL_64_after_hwframe+0x77/0x7f"
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T05:17:44.780Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/185427b5f7a209254c85c18aad5a4a8e009b2f30"
},
{
"url": "https://git.kernel.org/stable/c/07aa4a8ebacde3d0ba50f60d2964f274ee7629bc"
},
{
"url": "https://git.kernel.org/stable/c/e037c1250cc90e7aacb002357d1b0399fc65ecfc"
},
{
"url": "https://git.kernel.org/stable/c/6b38a5b8ee951e5b244e9a3c3d28d0f5e7c51411"
},
{
"url": "https://git.kernel.org/stable/c/8614a8f7e81edd34c9f67e454e7024fd12a2a341"
},
{
"url": "https://git.kernel.org/stable/c/bb44a7690a4d553da705919cf666a80f5ca9011c"
},
{
"url": "https://git.kernel.org/stable/c/610a0d2a35496738e1472fb0f318d5008a1c634f"
},
{
"url": "https://git.kernel.org/stable/c/93612d48fa42b3d1a637eb9279e15281c611c000"
}
],
"title": "ocfs2: rebase copied fsdlm LVB pointers in locking_state",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74351",
"datePublished": "2026-08-15T05:58:37.967Z",
"dateReserved": "2026-08-15T05:44:03.886Z",
"dateUpdated": "2026-08-17T05:17:44.780Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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