CVE-2026-80644 - Vulnerability Details

- ocfs2: don't BUG_ON an invalid journal dinode

Description

In the Linux kernel, the following vulnerability has been resolved:

ocfs2: don't BUG_ON an invalid journal dinode

[BUG]
A fuzzed OCFS2 image can corrupt the current slot journal dinode while
mount is still in progress. The mount path first reports the invalid
journal block and then crashes in shutdown:

kernel BUG at fs/ocfs2/journal.c:1034!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
RIP: 0010:ocfs2_journal_toggle_dirty+0x2d6/0x340 fs/ocfs2/journal.c:1034
Call Trace:
ocfs2_journal_shutdown+0x414/0xc30 fs/ocfs2/journal.c:1116
ocfs2_mount_volume fs/ocfs2/super.c:1785 [inline]
ocfs2_fill_super+0x30a9/0x3cd0 fs/ocfs2/super.c:1083
get_tree_bdev_flags+0x38b/0x640 fs/super.c:1698
get_tree_bdev+0x24/0x40 fs/super.c:1721
ocfs2_get_tree+0x21/0x30 fs/ocfs2/super.c:1184
vfs_get_tree+0x9a/0x370 fs/super.c:1758
fc_mount fs/namespace.c:1199 [inline]
do_new_mount_fc fs/namespace.c:3642 [inline]
do_new_mount fs/namespace.c:3718 [inline]
path_mount+0x5b8/0x1ea0 fs/namespace.c:4028
do_mount fs/namespace.c:4041 [inline]
__do_sys_mount fs/namespace.c:4229 [inline]
__se_sys_mount fs/namespace.c:4206 [inline]
__x64_sys_mount+0x282/0x320 fs/namespace.c:4206
...

[CAUSE]
ocfs2_journal_toggle_dirty() used to return -EIO when journal->j_bh no
longer contained a valid dinode, because the startup and shutdown paths
already handled that failure. Commit 10995aa2451a
("ocfs2: Morph the haphazard OCFS2_IS_VALID_DINODE() checks.") changed
the check to a BUG_ON() under the assumption that the journal dinode had
already been validated. That turns an unexpected invalid journal dinode
during mount teardown into a kernel crash instead of a normal mount
failure.

[FIX]
Replace the BUG_ON() with WARN_ON() and return -EIO. This keeps the
invariant warning for debugging, but restores the original behavior of
failing startup or shutdown cleanly instead of panicking the kernel.

Published: 2026-08-28

Score: 5.5 Medium

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Impact

The vulnerability arises from a BUG_ON that is triggered when the kernel detects an invalid journal dinode during OCFS2 unmount. Instead of a graceful failure, the kernel panics, causing an immediate system crash and disabling all services. This is a classic denial‑of‑service scenario where a single corrupted journal can bring a system down.

Affected Systems

All Linux kernels that incorporate the OCFS2 filesystem and contain the buggy BUG_ON check between commit 10995aa2451a and the subsequent patch are affected. The CVE notes do not enumerate specific kernel versions, implying that any build with the fault remains vulnerable until the BUG_ON is replaced by a WARN_ON and an error return.

Risk and Exploitability

An attacker who can supply a malformed or corrupted OCFS2 volume during mount can trigger the fault. The EPSS score is less than 1 %, indicating a low but non‑zero likelihood of exploitation. The CVSS score of 5.5 reflects moderate severity. The vulnerability is not listed in CISA KEV, so public exploits have not been observed yet. Nonetheless, the impact is severe – a single kernel panic can cripple a production environment.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Linux

unaffected

Version	Status	Constraints
`10995aa2451afa20b721cc7de856cae1a13dba57`	affected	< bf1d59cf2ac8a1730607ebaa0bc0dc6d00f197d0
`10995aa2451afa20b721cc7de856cae1a13dba57`	affected	< 86509c5296fe46ad6bcdd83931a53c2c6b7913a8
`10995aa2451afa20b721cc7de856cae1a13dba57`	affected	< 12c32a7350b670aaaaf2e01583d8648ec0c9755c
`10995aa2451afa20b721cc7de856cae1a13dba57`	affected	< b460f8d01a12061853d02c8fb693fb42450acd7d
`10995aa2451afa20b721cc7de856cae1a13dba57`	affected	< a06eec15596e5801bad59ad16cd2bf4f0fa839a1
`10995aa2451afa20b721cc7de856cae1a13dba57`	affected	< 3852478d34c7baa490ba9c7374ee901a56eea577
`10995aa2451afa20b721cc7de856cae1a13dba57`	affected	< 5b33f99f3e48465bd93219495381a5aef4fa967f
`10995aa2451afa20b721cc7de856cae1a13dba57`	affected	< c0438198c28b1d22c272751af5e717c11d9fa8dd

Linux

affected

Version	Status	Constraints
`2.6.29`	affected	—
`0`	unaffected	< 2.6.29
`5.10.261`	unaffected	≤ 5.10.*
`5.15.212`	unaffected	≤ 5.15.*
`6.1.178`	unaffected	≤ 6.1.*
`6.6.145`	unaffected	≤ 6.6.*
`6.12.97`	unaffected	≤ 6.12.*
`6.18.40`	unaffected	≤ 6.18.*
`7.1.5`	unaffected	≤ 7.1.*
`7.2`	unaffected	≤ *

No data.

Vendor Product Confidence Versions

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`[10995aa2451afa20b721cc7de856cae1a13dba57,bf1d59cf2ac8a1730607ebaa0bc0dc6d00f197d0)`	affected	code_commit	—
`[10995aa2451afa20b721cc7de856cae1a13dba57,86509c5296fe46ad6bcdd83931a53c2c6b7913a8)`	affected	code_commit	—
`[10995aa2451afa20b721cc7de856cae1a13dba57,12c32a7350b670aaaaf2e01583d8648ec0c9755c)`	affected	code_commit	—
`[10995aa2451afa20b721cc7de856cae1a13dba57,b460f8d01a12061853d02c8fb693fb42450acd7d)`	affected	code_commit	—
`[10995aa2451afa20b721cc7de856cae1a13dba57,a06eec15596e5801bad59ad16cd2bf4f0fa839a1)`	affected	code_commit	—
`[10995aa2451afa20b721cc7de856cae1a13dba57,3852478d34c7baa490ba9c7374ee901a56eea577)`	affected	code_commit	—
`[10995aa2451afa20b721cc7de856cae1a13dba57,5b33f99f3e48465bd93219495381a5aef4fa967f)`	affected	code_commit	—
`[10995aa2451afa20b721cc7de856cae1a13dba57,c0438198c28b1d22c272751af5e717c11d9fa8dd)`	affected	code_commit	—

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`2.6.29`	affected	semver	—
`[0,2.6.29)`	unaffected	semver	—
`[5.10.261,5.11.0)`	unaffected	semver	—
`[5.15.212,5.16.0)`	unaffected	semver	—
`[6.1.178,6.2.0)`	unaffected	semver	—
`[6.6.145,6.7.0)`	unaffected	semver	—
`[6.12.97,6.13.0)`	unaffected	semver	—
`[6.18.40,6.19.0)`	unaffected	semver	—
`[7.1.5,7.2.0)`	unaffected	semver	—
`[7.2,*]`	unaffected	generic	—

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Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

Apply a Linux kernel update that replaces the BUG_ON with a WARN_ON and returns -EIO, restoring normal error handling.
If the kernel cannot be updated immediately, disable or unload the OCFS2 module to prevent the crash when a corrupted filesystem is mounted.
Validate OCFS2 images for integrity before mounting, using checksums or dedicated verification tools to avoid providing corrupted journals to the kernel.

Generated by OpenCVE AI on September 2, 2026 at 07:58 UTC.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00176.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/stable/c/12c32a7350b670aaaaf2e01583d8648ec0c9755c
https://git.kernel.org/stable/c/3852478d34c7baa490ba9c7374ee901a56eea577
https://git.kernel.org/stable/c/5b33f99f3e48465bd93219495381a5aef4fa967f
https://git.kernel.org/stable/c/86509c5296fe46ad6bcdd83931a53c2c6b7913a8
https://git.kernel.org/stable/c/a06eec15596e5801bad59ad16cd2bf4f0fa839a1
https://git.kernel.org/stable/c/b460f8d01a12061853d02c8fb693fb42450acd7d
https://git.kernel.org/stable/c/bf1d59cf2ac8a1730607ebaa0bc0dc6d00f197d0
https://git.kernel.org/stable/c/c0438198c28b1d22c272751af5e717c11d9fa8dd
https://lore.kernel.org/linux-cve-announce/2026082842-CVE-2026-80644-0834@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2026-80644
https://www.cve.org/CVERecord?id=CVE-2026-80644

History

Wed, 02 Sep 2026 06:15:00 +0000

Type	Values Removed	Values Added
Weaknesses	CWE-665

Wed, 02 Sep 2026 00:15:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-617
References		https://lore.kernel.org/linux-cve-announce/2026082842-CVE-2026-80644-0834@gregkh/T https://nvd.nist.gov/vuln/detail/CVE-2026-80644 https://www.cve.org/CVERecord?id=CVE-2026-80644
Metrics	threat_severity `None`	cvssV3_1 `{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}` threat_severity `Moderate`

Fri, 28 Aug 2026 18:15:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-665

Fri, 28 Aug 2026 15:15:00 +0000

Type	Values Removed	Values Added
Weaknesses	CWE-390

Fri, 28 Aug 2026 09:45:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-390

Fri, 28 Aug 2026 07:30:00 +0000

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: ocfs2: don't BUG_ON an invalid journal dinode [BUG] A fuzzed OCFS2 image can corrupt the current slot journal dinode while mount is still in progress. The mount path first reports the invalid journal block and then crashes in shutdown: kernel BUG at fs/ocfs2/journal.c:1034! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI RIP: 0010:ocfs2_journal_toggle_dirty+0x2d6/0x340 fs/ocfs2/journal.c:1034 Call Trace: ocfs2_journal_shutdown+0x414/0xc30 fs/ocfs2/journal.c:1116 ocfs2_mount_volume fs/ocfs2/super.c:1785 [inline] ocfs2_fill_super+0x30a9/0x3cd0 fs/ocfs2/super.c:1083 get_tree_bdev_flags+0x38b/0x640 fs/super.c:1698 get_tree_bdev+0x24/0x40 fs/super.c:1721 ocfs2_get_tree+0x21/0x30 fs/ocfs2/super.c:1184 vfs_get_tree+0x9a/0x370 fs/super.c:1758 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3642 [inline] do_new_mount fs/namespace.c:3718 [inline] path_mount+0x5b8/0x1ea0 fs/namespace.c:4028 do_mount fs/namespace.c:4041 [inline] __do_sys_mount fs/namespace.c:4229 [inline] __se_sys_mount fs/namespace.c:4206 [inline] __x64_sys_mount+0x282/0x320 fs/namespace.c:4206 ... [CAUSE] ocfs2_journal_toggle_dirty() used to return -EIO when journal->j_bh no longer contained a valid dinode, because the startup and shutdown paths already handled that failure. Commit 10995aa2451a ("ocfs2: Morph the haphazard OCFS2_IS_VALID_DINODE() checks.") changed the check to a BUG_ON() under the assumption that the journal dinode had already been validated. That turns an unexpected invalid journal dinode during mount teardown into a kernel crash instead of a normal mount failure. [FIX] Replace the BUG_ON() with WARN_ON() and return -EIO. This keeps the invariant warning for debugging, but restores the original behavior of failing startup or shutdown cleanly instead of panicking the kernel.
Title		ocfs2: don't BUG_ON an invalid journal dinode
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/12c32a7350b670aaaaf2e01583d8648ec0c9755c https://git.kernel.org/stable/c/3852478d34c7baa490ba9c7374ee901a56eea577 https://git.kernel.org/stable/c/5b33f99f3e48465bd93219495381a5aef4fa967f https://git.kernel.org/stable/c/86509c5296fe46ad6bcdd83931a53c2c6b7913a8 https://git.kernel.org/stable/c/a06eec15596e5801bad59ad16cd2bf4f0fa839a1 https://git.kernel.org/stable/c/b460f8d01a12061853d02c8fb693fb42450acd7d https://git.kernel.org/stable/c/bf1d59cf2ac8a1730607ebaa0bc0dc6d00f197d0 https://git.kernel.org/stable/c/c0438198c28b1d22c272751af5e717c11d9fa8dd

Subscriptions

Linux Linux Kernel

MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2026-08-28T06:48:55.076Z

Updated: 2026-08-28T06:48:55.076Z

Reserved: 2026-08-26T14:34:25.778Z

Link: CVE-2026-80644

Vulnrichment

No data.

NVD

Status : Received

Published: 2026-08-28T08:16:49.290

Modified: 2026-08-28T08:16:49.290

Link: CVE-2026-80644

Redhat

Severity : Moderate

Publid Date: 2026-08-28T00:00:00Z

Links: CVE-2026-80644 - Bugzilla

OpenCVE Enrichment

Updated: 2026-09-02T08:00:14Z

Weaknesses

CWE-617
Reachable Assertion

Impact

Affected Systems

Risk and Exploitability

Tracking

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

Subscriptions

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