CVE-2026-93198 PUBLISHED

dm-pcache: validate the persisted dirty_tail chain at load

Assigner: Linux
Reserved: 17.09.2026 Published: 17.09.2026 Updated: 17.09.2026

In the Linux kernel, the following vulnerability has been resolved:

dm-pcache: validate the persisted dirty_tail chain at load

The writeback worker follows the persisted dirty_tail chain, which is decoded from the cache device independently of the key_tail chain that cache_replay() walks and bounds. A crafted image, whose on-media fields are authenticated only by a crc32c with a fixed seed, can aim dirty_tail at a chain of last ksets that never terminates, so cache_writeback_fn() re-arms itself with no delay forever.

Walk the dirty_tail chain once at load with the same hop cap cache_replay() uses and fail the table load with -EIO if it does not reach an end within n_segs hops.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 to 8195cf3f4a82ef49d9b0651c507ed0784caf23fb (excl.)
  • affected from 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 to 4822a030929e0e77aa380722dc42e3e4c9edd346 (excl.)
  • affected from 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 to 58d620ee9e01d4bdbceaf2ae1450d307a2a9d58b (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 6.18 is affected
  • unaffected from 0 to 6.18 (excl.)
  • unaffected from 6.18.52 to 6.18.* (incl.)
  • unaffected from 7.2.6 to 7.2.* (incl.)
  • unaffected from 7.3-rc1 to * (incl.)

References