Junglewise Threat Intelligence

CVE-2025-38659: Linux Kernel NULL pointer dereference in GFS2 self-recovery

CVE-2025-38659 · Severity: medium · CVSS 5.5 · Published 2025-08-22

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability in the Linux kernel's GFS2 file system could allow a local user to cause a system crash. The issue occurs when a cluster node attempts to perform a 'self-recovery' after withdrawing from a shared file system. This can lead to a service outage or system instability, affecting the availability of data stored on GFS2 volumes.

Technical details

A vulnerability exists in the GFS2 (Global File System 2) component of the Linux kernel during node withdrawal. When a node is the sole mounter of a filesystem and attempts to withdraw, the 'self-recovery' logic in gfs2_recover_func() dereferences sdp->sd_jdesc->jd_inode. Depending on the kernel version, this results in either a use-after-free or a NULL pointer dereference. An attacker with local access could potentially trigger this condition to cause a kernel panic (Denial of Service). The fix involves removing the problematic self-recovery mechanism, ensuring that recovery is instead handled by the next node to mount the filesystem.

Affected products

  • Linux Linux Kernel 5.7 to 6.6.102, 6.7 to 6.12.42, 6.13 to 6.15.10, 6.16 to 6.16.1

Timeline

  • 2025-08-22: disclosed: Initial publication of the vulnerability advisory.
  • 2025-08-22: advisory: CVE-2025-38659 published to NVD.

References

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