CVE-2026-72161

Received Received - Intake

NULL Pointer Dereference in OCFS2 Filesystem

Publication date: 2026-08-15

Last updated on: 2026-08-17

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: ocfs2: add journal NULL check in ocfs2_checkpoint_inode() During unmount, ocfs2_journal_shutdown() frees the journal and sets osb->journal to NULL. Later, when VFS evicts remaining cached inodes, ocfs2_evict_inode() -> ocfs2_clear_inode() -> ocfs2_checkpoint_inode() -> ocfs2_ci_fully_checkpointed() dereferences osb->journal, causing a NULL pointer dereference. Fix this by adding a NULL check for osb->journal in ocfs2_checkpoint_inode(). If the journal is NULL, it has already been fully flushed and destroyed during shutdown, so there is nothing to checkpoint.

CVSS Scores

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Meta Information

Published

2026-08-15

Last Modified

2026-08-17

Generated

2026-09-04

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-03

NVD

CVE-2026-72161

EUVD

EUVD-2026-58919

Affected Vendors & Products

Vendor	Product	Version / Range
oracle	ocfs2	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This is a NULL pointer dereference vulnerability in the Linux kernel's OCFS2 file system. During unmount, the journal is freed and set to NULL. Later, when the VFS evicts cached inodes, it calls ocfs2_checkpoint_inode() which dereferences the now-NULL journal pointer, causing a crash.

Detection Guidance

This vulnerability is specific to the Linux kernel's OCFS2 filesystem and occurs during unmount operations. Detection requires checking kernel logs for NULL pointer dereference errors related to ocfs2_checkpoint_inode or ocfs2_evict_inode. Monitor logs with commands like dmesg | grep -i 'ocfs2' or journalctl -k | grep -i 'ocfs2' after unmounting OCFS2 volumes.

Impact Analysis

This vulnerability can cause system crashes when unmounting OCFS2 file systems, leading to data loss or denial of service. It affects systems using OCFS2 during normal shutdown or unmount operations.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards. It is a Linux kernel issue causing a NULL pointer dereference during unmount operations in the OCFS2 filesystem, which could lead to system crashes but does not involve data exposure or privacy violations.

Mitigation Strategies

Apply the kernel patch that adds the NULL check in ocfs2_checkpoint_inode(). Until patched, avoid unmounting OCFS2 volumes while processes are still accessing files. Ensure regular kernel updates are applied to receive security fixes.

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