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]
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]
Metrics
Affected Vendors & Products
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Fixes
Solution
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Workaround
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References
History
Sat, 15 Aug 2026 06:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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] | |
| Title | afs: Remove setting of AS_RELEASE_ALWAYS for symlinks and mountpoints | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-15T05:56:11.017Z
Reserved: 2026-08-09T03:40:39.922Z
Link: CVE-2026-72377
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-08-15T06:22:11.180
Modified: 2026-08-15T06:22:11.180
Link: CVE-2026-72377
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.