CVE-2026-89491: Linux kernel · ocfs2: cluster: don't sleep while holding o2hb_live_lock in o2hb_region_pin()
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 14:05 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch series addressing these issues has been released, reworking the o2hb_region_pin() function and related code to avoid sleeping while holding spinlocks and fixing error handling. Users should apply the official Linux kernel updates containing these fixes. Patch status is confirmed by the resolved vulnerability description. No additional mitigation is indicated.
Description
A vulnerability in the Linux kernel's ocfs2 cluster component was resolved by reworking the o2hb_region_pin() function to avoid sleeping while holding the o2hb_live_lock spinlock. The original implementation caused BUGs under CONFIG_DEBUG_ATOMIC_SLEEP due to sleeping while holding a spinlock, introduced lock order inversions that could lead to deadlocks, and leaked counters on partial failures, leaving heartbeat regions unprotected. The fix involves dropping the spinlock before sleeping calls, avoiding lock order inversion, and properly handling error paths to prevent resource leaks.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89491 (opens in a new tab)
- git.kernel.org/stable/c/470212a5eefabcc16b8e2f7fe2844b8737fe571c (opens in a new tab)
- git.kernel.org/stable/c/49002acc520c61002ad195894ac391c94317d3ba (opens in a new tab)
- git.kernel.org/stable/c/af09df89db9a68a1d76df0f75667998135bc8d65 (opens in a new tab)
- git.kernel.org/stable/c/ce035f208d68b812d83e5482980f2b1c88a9cd94 (opens in a new tab)
- msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-89491.json (opens in a new tab)
- support.microsoft.com/lifecycle (opens in a new tab)
- first.org/cvss (opens in a new tab)
- ubuntu.com/security/CVE-2026-89491 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89491 (opens in a new tab)
- git.kernel.org/linus/af09df89db9a68a1d76df0f75667998135bc8d65 (opens in a new tab)