CVE-2026-72377: afs: Remove setting of AS_RELEASE_ALWAYS for symlinks and mountpoints
In the Linux kernel, the following vulnerability has been resolved:
afs: Remove setting of ASRELEASEALWAYS for symlinks and mountpoints
Regular AFS files correctly use afsfileaops which have releasefolio set as netfsreleasefolio, so ASRELEASEALWAYS is valid for them when fscache is enabled (set via afsvnodesetcache()). Symlinks and mountpoints in AFS use afsdiraops, which does not provide a releasefolio callback. However, afsapplystatus() unconditionally calls mappingsetreleasealways() for these.
In such case when memory management code attempts to release folios, filemapreleasefolio() checks folioneedsrelease() which returns true due to ASRELEASEALWAYS being set. Since there is no releasefolio callback, it falls through to trytofreebuffers(), which at present expects bufferheads to be not null. For symlinks and mountpoints without bufferheads, this causes pointer dereference.
[dh: Added more bits that were missed]
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-72377?
The severity of CVE-2026-72377 is rated at risk level 44.
How do I fix CVE-2026-72377?
To fix CVE-2026-72377, ensure that your system's Linux kernel is updated to a version that resolves this issue.
What components are affected by CVE-2026-72377?
CVE-2026-72377 affects the AFS (Andrew File System) functionality within the Linux kernel.
What type of vulnerability is CVE-2026-72377?
CVE-2026-72377 is related to the improper handling of AS_RELEASE_ALWAYS for symlinks and mountpoints in the AFS implementation.
When was CVE-2026-72377 published?
CVE-2026-72377 was published on August 15, 2026.