CVE-2026-80957: dm-pcache: detect a cycle in the last-kset chain during replay
In the Linux kernel, the following vulnerability has been resolved:
dm-pcache: detect a cycle in the last-kset chain during replay
cachereplay() follows the on-media last-kset chain by nextcachesegid with no condresched(). A forged chain that points back into a segment it has already visited makes the replay loop follow it forever.
Cap the last-kset hops at cache->nsegs; a valid chain visits each segment at most once.
Affected Software
Event History
Frequently Asked Questions
Which systems are exposed?
Systems using the Linux kernel dm-pcache component are exposed when cache replay processes on-media last-kset metadata.
What does exploitation require?
An attacker needs to forge the on-media last-kset chain so that next_cache_seg_id points to a cache segment that has already been visited.
What is the impact of a forged chain?
During cache_replay(), the kernel can follow the cyclic chain indefinitely, causing the replay loop not to complete.