CVE-2026-99204 (GCVE-0-2026-99204)
Vulnerability from cvelistv5
Published
2026-10-28 10:35
Modified
2026-10-28 10:35
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
ocfs2/dlm: Protect the recovery list during debugfs reads
Recovery participant records must remain alive while debug_state_print()
walks reco.node_data and formats their fields. The formatter holds
dlm->spinlock, but the recovery participant list is protected by
dlm_reco_state_lock. In particular, dlm_destroy_recovery_area() detaches
the list under dlm_reco_state_lock and frees the detached records after
releasing it. A concurrent debugfs open can therefore read freed memory.
Protect the participant traversal and field reads in debug_state_print()
with dlm_reco_state_lock, matching the existing list writers. This also
serializes the traversal against list_add_tail() during recovery-area
initialization. Make the existing lock available to the debug code
through dlmcommon.h; the lock remains internal to the OCFS2 DLM module.
Release dlm->spinlock after formatting the other domain state and before
acquiring dlm_reco_state_lock, so the debug reader does not nest the two
locks. Leave recovery list insertion, detachment and freeing unchanged.
KASAN report as below:
BUG: KASAN: slab-use-after-free in debug_state_open+0x1169/0x12d0
Read of size 4 at addr ffff88810662ef80 by task dlm-state-stres/896
CPU: 1 UID: 0 PID: 896 Comm: dlm-state-stres Not tainted 7.3.0-rc4-next-20260921-pmb-ocfs2-functional-v1+ #1 PREEMPT(lazy)
Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x93/0xd0
print_report+0xce/0x630
? debug_state_open+0x1169/0x12d0
? srso_alias_return_thunk+0x5/0xfbef5
? __virt_addr_valid+0x20e/0x420
? debug_state_open+0x1169/0x12d0
kasan_report+0xe0/0x110
? debug_state_open+0x1169/0x12d0
debug_state_open+0x1169/0x12d0
? __pfx_debug_state_open+0x10/0x10
full_proxy_open_regular+0x193/0x310
do_dentry_open+0x595/0x12d0
? __pfx_full_proxy_open_regular+0x10/0x10
vfs_open_consume+0xd1/0x400
? srso_alias_return_thunk+0x5/0xfbef5
path_openat+0x18d0/0x2020
? __pfx_path_openat+0x10/0x10
do_file_open+0x21e/0x470
? __pfx_do_file_open+0x10/0x10
? _raw_spin_unlock+0x23/0x40
? srso_alias_return_thunk+0x5/0xfbef5
? alloc_fd+0x3a6/0x6b0
do_sys_openat2+0xf4/0x1b0
? __pfx_do_sys_openat2+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? __fput+0x5b5/0xa60
__x64_sys_openat+0x136/0x1e0
? __pfx___x64_sys_openat+0x10/0x10
do_syscall_64+0x114/0x620
entry_SYSCALL_64_after_hwframe+0x77/0x7f
[Register dump omitted.]
</TASK>
Allocated by task 880:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_kmalloc+0xaa/0xb0
__kmalloc_cache_noprof+0x28d/0x610
dlm_remaster_locks+0x147/0x1d90
dlm_do_recovery+0xde1/0x1580
dlm_recovery_thread+0x109/0x300
kthread+0x351/0x460
ret_from_fork+0x659/0x940
ret_from_fork_asm+0x1a/0x30
Freed by task 880:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x5f/0x80
kfree+0x308/0x580
dlm_destroy_recovery_area+0x285/0x460
dlm_remaster_locks+0x17c4/0x1d90
dlm_do_recovery+0xde1/0x1580
dlm_recovery_thread+0x109/0x300
kthread+0x351/0x460
ret_from_fork+0x659/0x940
ret_from_fork_asm+0x1a/0x30
The buggy address belongs to the object at ffff88810662ef80
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
freed 32-byte region [ffff88810662ef80, ffff88810662efa0)
[Page and memory-state dumps omitted.]
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/ocfs2/dlm/dlmcommon.h",
"fs/ocfs2/dlm/dlmdebug.c",
"fs/ocfs2/dlm/dlmrecovery.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "04d4571c00db61a9664f387752fa05cb3c08a537",
"status": "affected",
"version": "007dce53a29ccffc000ab5373d188f73881390fd",
"versionType": "git"
},
{
"lessThan": "2bc426a32bfb78868c7f76d9547132837b6b5284",
"status": "affected",
"version": "007dce53a29ccffc000ab5373d188f73881390fd",
"versionType": "git"
},
{
"lessThan": "4c435828932bf46f29860e4a0375bcae101b778a",
"status": "affected",
"version": "007dce53a29ccffc000ab5373d188f73881390fd",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/ocfs2/dlm/dlmcommon.h",
"fs/ocfs2/dlm/dlmdebug.c",
"fs/ocfs2/dlm/dlmrecovery.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.26"
},
{
"lessThan": "2.6.26",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.59",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.13",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.59",
"versionStartIncluding": "2.6.26",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.13",
"versionStartIncluding": "2.6.26",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3",
"versionStartIncluding": "2.6.26",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2/dlm: Protect the recovery list during debugfs reads\n\nRecovery participant records must remain alive while debug_state_print()\nwalks reco.node_data and formats their fields. The formatter holds\ndlm-\u003espinlock, but the recovery participant list is protected by\ndlm_reco_state_lock. In particular, dlm_destroy_recovery_area() detaches\nthe list under dlm_reco_state_lock and frees the detached records after\nreleasing it. A concurrent debugfs open can therefore read freed memory.\n\nProtect the participant traversal and field reads in debug_state_print()\nwith dlm_reco_state_lock, matching the existing list writers. This also\nserializes the traversal against list_add_tail() during recovery-area\ninitialization. Make the existing lock available to the debug code\nthrough dlmcommon.h; the lock remains internal to the OCFS2 DLM module.\n\nRelease dlm-\u003espinlock after formatting the other domain state and before\nacquiring dlm_reco_state_lock, so the debug reader does not nest the two\nlocks. Leave recovery list insertion, detachment and freeing unchanged.\n\nKASAN report as below:\n\n BUG: KASAN: slab-use-after-free in debug_state_open+0x1169/0x12d0\n Read of size 4 at addr ffff88810662ef80 by task dlm-state-stres/896\n\n CPU: 1 UID: 0 PID: 896 Comm: dlm-state-stres Not tainted 7.3.0-rc4-next-20260921-pmb-ocfs2-functional-v1+ #1 PREEMPT(lazy)\n Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n Call Trace:\n \u003cTASK\u003e\n dump_stack_lvl+0x93/0xd0\n print_report+0xce/0x630\n ? debug_state_open+0x1169/0x12d0\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? __virt_addr_valid+0x20e/0x420\n ? debug_state_open+0x1169/0x12d0\n kasan_report+0xe0/0x110\n ? debug_state_open+0x1169/0x12d0\n debug_state_open+0x1169/0x12d0\n ? __pfx_debug_state_open+0x10/0x10\n full_proxy_open_regular+0x193/0x310\n do_dentry_open+0x595/0x12d0\n ? __pfx_full_proxy_open_regular+0x10/0x10\n vfs_open_consume+0xd1/0x400\n ? srso_alias_return_thunk+0x5/0xfbef5\n path_openat+0x18d0/0x2020\n ? __pfx_path_openat+0x10/0x10\n do_file_open+0x21e/0x470\n ? __pfx_do_file_open+0x10/0x10\n ? _raw_spin_unlock+0x23/0x40\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? alloc_fd+0x3a6/0x6b0\n do_sys_openat2+0xf4/0x1b0\n ? __pfx_do_sys_openat2+0x10/0x10\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? __fput+0x5b5/0xa60\n __x64_sys_openat+0x136/0x1e0\n ? __pfx___x64_sys_openat+0x10/0x10\n do_syscall_64+0x114/0x620\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n [Register dump omitted.]\n \u003c/TASK\u003e\n\n Allocated by task 880:\n kasan_save_stack+0x33/0x60\n kasan_save_track+0x14/0x30\n __kasan_kmalloc+0xaa/0xb0\n __kmalloc_cache_noprof+0x28d/0x610\n dlm_remaster_locks+0x147/0x1d90\n dlm_do_recovery+0xde1/0x1580\n dlm_recovery_thread+0x109/0x300\n kthread+0x351/0x460\n ret_from_fork+0x659/0x940\n ret_from_fork_asm+0x1a/0x30\n\n Freed by task 880:\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+0x308/0x580\n dlm_destroy_recovery_area+0x285/0x460\n dlm_remaster_locks+0x17c4/0x1d90\n dlm_do_recovery+0xde1/0x1580\n dlm_recovery_thread+0x109/0x300\n kthread+0x351/0x460\n ret_from_fork+0x659/0x940\n ret_from_fork_asm+0x1a/0x30\n\n The buggy address belongs to the object at ffff88810662ef80\n which belongs to the cache kmalloc-32 of size 32\n The buggy address is located 0 bytes inside of\n freed 32-byte region [ffff88810662ef80, ffff88810662efa0)\n\n [Page and memory-state dumps omitted.]"
}
],
"providerMetadata": {
"dateUpdated": "2026-10-28T10:35:58.336Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/04d4571c00db61a9664f387752fa05cb3c08a537"
},
{
"url": "https://git.kernel.org/stable/c/2bc426a32bfb78868c7f76d9547132837b6b5284"
},
{
"url": "https://git.kernel.org/stable/c/4c435828932bf46f29860e4a0375bcae101b778a"
}
],
"title": "ocfs2/dlm: Protect the recovery list during debugfs reads",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-99204",
"datePublished": "2026-10-28T10:35:58.336Z",
"dateReserved": "2026-09-25T10:25:14.400Z",
"dateUpdated": "2026-10-28T10:35:58.336Z",
"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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