Affected: Linux

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

dm-integrity: fix buffer overflow in inline mode with large tag size

In inline mode, dm_integrity_check and dm_integrity_inline_recheck compute the checksum of each block into an on-stack buffer of HASH_MAX_DIGESTSIZE bytes. integrity_sector_checksum pads its result with zeroes up to the tag size, so if the tag size is larger than HASH_MAX_DIGESTSIZE, the padding runs past the end of the buffer. With CONFIG_STACKPROTECTOR the kernel panics in dm_integrity_check on the first read.

Enlarge both buffers to hold MAX_TAG_SIZE bytes, as commit b93b6643e9b5 ("dm integrity: fix a crash with unusually large tag size") did for integrity_metadata.

Note that this is not a security bug because the buffer overflow can only be triggered by root.