CVE-2023-53810
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().
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.14%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.14% probability · 4th percentile
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/7d206ec7a04e8545828191b6ea8b49d3ea61391f
- https://git.kernel.org/stable/c/874bdf43b4a7dc5463c31508f62b3e42eb237b08
- https://git.kernel.org/stable/c/92d5d233b9ff531cf9cc36ab4251779e07adb633
- https://git.kernel.org/stable/c/9cd1e566676bbcb8a126acd921e4e194e6339603
- https://git.kernel.org/stable/c/b278570e2c59d538216f8b656e97680188a8fba4
- https://git.kernel.org/stable/c/d206f79d9cd658665b37ce8134c6ec849ac7af0c
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.