Vulnerability · CVE-2026-99204

CVE-2026-99204: ocfs2/dlm: Protect the recovery list during debugfs reads

Published Oct 28, 2026 · catalog updated Oct 31, 2026 · Red Hat Red Hat Enterprise Linux

Last checked Nov 6, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-99204. EPSS is 0.17%. Act only if a listed version of Red Hat Red Hat Enterprise Linux is installed.

Gaps on this record

No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity: Medium4.1
Known exploitation: Not in CISA/VulnCheck KEV
EPSS: 0.17%
Remediation: Advisory link
Affected products: Debian:12 linux · Debian:13 linux · Debian:14 linux · Linux Kernel · linux kernel · vendor Linux Linux

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: 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

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

Debian:12 linux6.1.106-1, 6.1.106-2, 6.1.106-3
Debian:13 linux6.12.100-1, 6.12.101-1, 6.12.105-1
Debian:14 linux6.12.100-1, 6.12.101-1, 6.12.105-1
Linux Kernel2.6.26 → 5.10.273; 5.11.0 → 5.15.224; 5.16.0 → 6.1.191
linux kernelversion unspecified
vendor Linux Linuxversion unspecified

How to fix CVE-2026-99204

Upgrade
CVE-2026-99204 lists a fix boundary at 5.10.273. Compare the installed build with that boundary before you change production.
Version check
Seen in 6.1.106-1 · 9 other packages on the advisory
Advisory
Open the bsi record and follow its fix.
Official advisories

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-99204. EPSS is 0.17%. Act only if a listed version of Red Hat Red Hat Enterprise Linux is installed.

Which versions are affected?

Compare what you have installed with Kernel 2.6.26 → 5.10.273; 5.11.0 → 5.15.224; 5.16.0 → 6.1.191. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-825. EPSS 0.17%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Debian security

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

Oct 28, 2026 · Tenable CVE Database
Detected
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() detac
Oct 28, 2026 · Trivy Vulnerability DB
Updated
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() detac
Oct 31, 2026 · OpenSSF OSV / OSV Scanner
Fix available
Kernel fixed in 5.10.273; Kernel fixed in 5.15.224; Kernel fixed in 6.1.191; Kernel fixed in 6.6.161
Oct 31, 2026 · OpenSSF OSV / OSV Scanner
Fix available
Kernel fixed in 5.10.273; 5.11.0
Oct 31, 2026 · OpenSSF OSV / OSV Scanner
Updated
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() detac

Sources

BSI CERT-BundGovernment advisoryCVE-2026-99204
Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff
wid.cert-bund.de
CVE.orgVulnerability recordCVE-2026-99204
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,
cve.org
FIRST EPSSExploitation probabilityCVE-2026-99204
30-day exploitation probability 0.17%
first.org
Linux Kernel CVEVendor advisoryCVE-2026-99204
From: Greg Kroah-Hartman Description =========== 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
git.kernel.org
OpenSSF OSV / OSV ScannerPackage advisoryCVE-2026-99204
ocfs2/dlm: Protect the recovery list during debugfs reads
osv.dev
Red Hat Security DataVendor advisoryCVE-2026-99204
kernel: kernel: Denial of Service via use-after-free in OCFS2 DLM debugfs interface
access.redhat.com
Tenable CVE DatabaseVulnerability recordCVE-2026-99204
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() detac
tenable.com
Trivy Vulnerability DBPackage advisoryDEBIAN-CVE-2026-99204
osv.dev

References

Freshness

Last verified in this catalog Nov 6, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

FIRST EPSSOct 31, 2026
OpenSSF OSV / OSV ScannerOct 31, 2026
Red Hat Security DataOct 30, 2026
BSI CERT-BundOct 30, 2026
CVE.orgOct 29, 2026
Trivy Vulnerability DBOct 28, 2026
Linux Kernel CVEOct 28, 2026
Tenable CVE DatabaseOct 28, 2026

Priority score

18/100

Evidence confidence: High

A vendor or government advisory agrees with at least one other source.

Confirmed exploitation0/30
EPSS probability1/20
CVSS severity6/15
Public exploit0/10
Internet exposure6/10
Product prevalence5/5
Detection0/5
Threat research0/5

Decision signals

Four separate signals — do not infer one from another.

Medium

CVSS severity
4.1 v3.1
Technical impact. Separate from exploitation likelihood.
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
EPSS probability
0.17% · p6.44%
Estimated probability of exploitation within 30 days (FIRST).
Known exploitation
No verified KEV listing
Evidence from CISA KEV or VulnCheck KEV only — not from EPSS alone.
Patch availability
Advisory link
A patch or advisory reference is linked. Open the original publisher for availability by product version.

Stacks

Debian Debian 12 Debian 13 Debian 14 Linux Red Hat

Weakness

CWE-825 MITRE definition

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