CVE-2026-80956

Description

In the Linux kernel, the following vulnerability has been resolved: dm-pcache: only hand out initialized cache segments get_cache_segment() scans the segment map up to cache->n_segs, the physical device segment count, but cache_segs_init() only initializes the first cache_info->n_segs segments. A crafted image with cache_info->n_segs smaller than the device count leaves the remaining pcache_cache_segment structs zeroed (segment.data == NULL), and the allocator can hand one to cache_kset_close(), which writes through the returned segment's data pointer with no NULL check. Bound the allocator's search to cache_info->n_segs so only initialized segments are ever returned. A conforming cache sets n_segs equal to the device segment count, so this rejects nothing legitimate.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

References

• https://git.kernel.org/stable/c/83e3116283ed2c6a6a1fa662862a4b4d7d2701a2 ↗
• https://git.kernel.org/stable/c/692037ae1a7cfacc2f0c22c6e034c1dfee0e553f ↗
• https://git.kernel.org/stable/c/2df0fc042e299bae3c0f60ea5cd2af9285658e9f ↗