CVE-2026-89491

/// Technical description

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"):

1) 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.

2) 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.

3) 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

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References