Commit 5d37a119 authored by Eric Biggers's avatar Eric Biggers
Browse files

fsverity: explicitly check that there is no algorithm 0 

Since libfsverity and some other code would break if 0 is ever allocated
as an FS_VERITY_HASH_ALG_* value, make fsverity_check_hash_algs()
explicitly check that there is no algorithm 0.

Link: https://lore.kernel.org/r/20230705211719.37713-1-ebiggers@kernel.org


Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
parent 06c2afb8

fs/verity/hash_algs.c

+8 −0
Original line number Diff line number Diff line
@@ -226,6 +226,14 @@ void __init fsverity_check_hash_algs(void) 
		if (!alg->name)

			continue;



		/*

		 * 0 must never be allocated as an FS_VERITY_HASH_ALG_* value,

		 * as it is reserved for users that use 0 to mean unspecified or

		 * a default value.  fs/verity/ itself doesn't care and doesn't

		 * have a default algorithm, but some users make use of this.

		 */

		BUG_ON(i == 0);



		BUG_ON(alg->digest_size > FS_VERITY_MAX_DIGEST_SIZE);



		/*