CVE-2026-90052
Description
AI Translation Available
In the Linux kernel, the following vulnerability has been resolved:
dm-integrity: fix buffer overflow with keyed discard
Since commit 68c5c42567bc ('dm-integrity: replace forgeable discard
filler with a keyed sector marker'), integrity_metadata computes a
checksum for every discarded block into the 'checksums' buffer.
integrity_sector_checksum always writes the whole digest. So if the tag
size is smaller than the digest size, the checksum of the last block
that fits into the buffer is written past the end of it. For example,
with hmac(sha256) and tag size 16, a 4MiB discard writes 16 bytes past
the kmalloc'ed page.
Fix this by subtracting extra_space from the buffer size when computing
max_blocks, like we do for writes.
https://git.kernel.org/stable/c/59e6f919d77d72ec79cbf171256f2f7819737580
https://git.kernel.org/stable/c/9988c1c9e0d1c78391e3d8e2817beb667470c76f
https://git.kernel.org/stable/c/dd08a645195f410f2dcaa40de379a45ce110e873