SB2026072377 - Race condition in Linux kernel xfs



SB2026072377 - Race condition in Linux kernel xfs

Published: July 23, 2026

Security Bulletin ID SB2026072377
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Race condition (CVE-ID: CVE-2026-64600)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a race condition in xfs_reflink_fill_cow_hole and xfs_reflink_fill_delalloc in the XFS reflink code when processing direct I/O writes after cycling the ILOCK. A local user can trigger a racing direct I/O write operation to cause a denial of service.

The issue occurs because a stale data fork mapping can be used after the ILOCK is dropped and reacquired, which can result in incorrect shared-block state during copy-on-write handling.


Remediation

Install update from vendor's website.