Vulnerability in Linux kernel (CVE-2026-89491)
Summary
Vulnerability in Linux kernel (CVE-2026-89491). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: cluster: don't sleep while holding o2hb_live_lock in o2hb_region_pin()
Patch series "ocfs2: cluster: o2hb_region_pin() fixes", v2.
This series fixes three related issues in o2hb_region_pin(), all are from
the original implementation in commit: 58a3158a5d17 ("ocfs2/cluster:
Pin/unpin o2hb regions"):
-
It is called with o2hb_live_lock (a spinlock) held, but the
underlying configfs_depend_item() sleeps (takes inode rwsem and
pins the filesystem). This triggers BUG under
CONFIG_DEBUG_ATOMIC_SLEEP. -
When called from the configfs drop_item callback, it creates a
lock order inversion: parent inode_lock -> configfs root
inode_lock, which can deadlock against subsystem unregistration
paths taking root -> parent. -
If pinning fails partway through o2hb_region_inc_user(), the
o2hb_dependent_users counter is leaked and partially-pinned
regions are never released, leaving heartbeat regions
unprotected on subsequent mounts.
Patch 1 reworks o2hb_region_pin() to drop o2hb_live_lock across each
sleeping configfs_depend_item() call, using a config_item reference to
keep the region alive while unlocked.
Patch 2 adds a from_callback parameter to select
configfs_depend_item_unlocked() when called from configfs context,
avoiding the inode_lock nesting.
Patch 3 fixes the error path in o2hb_region_inc_user() to unpin and
decrement the counter on failure.
This patch (of 3):
o2hb_regio…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-89491 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-89491" on the vendor's site.
CVE-2026-89491 (Linux kernel)
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web nvd.nist.gov
- web github.com