CVE-2023-53810: Linux

High severity, CVSS 7.8. EPSS: 0.1% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: blk-mq: release crypto keyslot before reporting I/O complete Once all I/O using a blk_crypto_key has completed, filesystems can call blk_crypto_evict_key(). However, the block layer currently doesn't call blk_crypto_put_keyslot() until the request is being freed, which happens after upper layers have been told (via bio_endio()) the I/O has completed. This causes a race condition where blk_crypto_evict_key() can see 'slot_refs != 0' without there being an actual bug. This makes __blk_crypto_evict_key() hit the 'WARN_ON_ONCE(atomic_read(&slot->slot_refs) != 0)' and return without doing anything, eventually causing a use-after-free in blk_crypto_reprogram_all_keys(). (This is a very rare bug and has only been seen when per-file keys are being used with fscrypt.) There are two options to fix this: either release the keyslot before bio_endio() is called on the request's last bio, or make __blk_crypto_evict_key() ignore slot_refs. Let's go with the first solution, since it preserves the ability to report bugs (via WARN_ON_ONCE) where a key is evicted while still in-use.

Affected products

• Linux Linux: from 5.8, before 5.10.180 (fixed in 5.10.180); from 5.11, before 5.15.111 (fixed in 5.15.111); from 5.16, before 6.1.28 (fixed in 6.1.28); from 6.2, before 6.2.15 (fixed in 6.2.15); from 6.3, before 6.3.2 (fixed in 6.3.2)

Published 2025-12-09. Last modified 2026-08-04.