From: Eric Biggers <ebiggers@kernel.org>
To: fsverity@lists.linux.dev
Subject: [PATCH] fsverity: explicitly check that there is no algorithm 0
Date: Wed, 5 Jul 2023 14:17:19 -0700 [thread overview]
Message-ID: <20230705211719.37713-1-ebiggers@kernel.org> (raw)
From: Eric Biggers <ebiggers@google.com>
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.
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
fs/verity/hash_algs.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/fs/verity/hash_algs.c b/fs/verity/hash_algs.c
index c598d20354763..6b08b1d9a7d7c 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);
/*
base-commit: ace1ba1c9038b30f29c5759bc4726bbed7748f15
--
2.41.0
reply other threads:[~2023-07-05 21:17 UTC|newest]
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