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author | Eric Biggers <ebiggers@google.com> | 2023-07-06 00:17:19 +0300 |
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committer | Eric Biggers <ebiggers@google.com> | 2023-07-12 08:49:18 +0300 |
commit | 5d37a1198068b099de47073411efc087d1b555ca (patch) | |
tree | 39624be68b704374ef11cfb3f53bc392a4143497 | |
parent | 06c2afb862f9da8dc5efa4b6076a0e48c3fbaaa5 (diff) | |
download | linux-5d37a1198068b099de47073411efc087d1b555ca.tar.xz |
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: Eric Biggers <ebiggers@google.com>
-rw-r--r-- | fs/verity/hash_algs.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/verity/hash_algs.c b/fs/verity/hash_algs.c index c598d2035476..6b08b1d9a7d7 100644 --- a/fs/verity/hash_algs.c +++ b/fs/verity/hash_algs.c @@ -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); /* |