CVE Catalog

CVE-2026-72377

Low risk· EPSS 10%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.20%

10th percentile - higher than 10% of all known CVEs

Summary

In the Linux kernel's AFS filesystem, the AS_RELEASE_ALWAYS flag is set for symlinks and mountpoints that use afs_dir_aops without a release_folio callback. This causes try_to_free_buffers() to be called with null buffer_heads, leading to a pointer dereference.

Risk Assessment

This could lead to a system crash (kernel panic) or memory corruption. The vulnerability affects systems using AFS with fscache enabled.

Recommendation

Apply the kernel patch that removes setting AS_RELEASE_ALWAYS for symlinks and mountpoints. Update your system to a kernel version with this fix.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: afs: Remove setting of AS_RELEASE_ALWAYS for symlinks and mountpoints Regular AFS files correctly use afs_file_aops which have release_folio set as netfs_release_folio, so AS_RELEASE_ALWAYS is valid for them when fscache is enabled (set via afs_vnode_set_cache()). Symlinks and mountpoints in AFS use afs_dir_aops, which does not provide a release_folio callback. However, afs_apply_status() unconditionally calls mapping_set_release_always() for these. In such case when memory management code attempts to release folios, filemap_release_folio() checks folio_needs_release() which returns true due to AS_RELEASE_ALWAYS being set. Since there is no release_folio callback, it falls through to try_to_free_buffers(), which at present expects buffer_heads to be not null. For symlinks and mountpoints without buffer_heads, this causes pointer dereference. [dh: Added more bits that were missed]

Vulnerability data from NVD (NIST) · CISA KEV · EPSS