CVE-2026-90333

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

dm-integrity: replace forgeable discard filler with a keyed sector marker

The discard-block check in dm_integrity_rw_tag() treats a stored tag

of all 0xf6 bytes (DISCARD_FILLER) as proof a block was discarded and

skips HMAC verification. allow_discards is only accepted in

dm-integrity's standalone mode. An attacker with raw write access to

the backing device, but without the integrity key, can stamp any block

with an all-0xf6 tag and have it served as authentic.

Add a new "allow_discards_keyed" target argument that marks discarded

blocks with a keyed checksum of (salt || sector) instead, computed by

integrity_discard_checksum().