diff options
author | Herbert Xu <herbert@gondor.apana.org.au> | 2016-11-17 22:07:58 +0800 |
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committer | Herbert Xu <herbert@gondor.apana.org.au> | 2016-11-18 22:34:10 +0800 |
commit | a8348bca2944d397a528772f5c0ccb47a8b58af4 (patch) | |
tree | a3afca8b46f4b4fa4c28755681821a178bfa7e18 /crypto | |
parent | a5a40d4624cd2328c69768f6eb41716fc249d7be (diff) | |
download | lwn-a8348bca2944d397a528772f5c0ccb47a8b58af4.tar.gz lwn-a8348bca2944d397a528772f5c0ccb47a8b58af4.zip |
crypto: algif_hash - Fix NULL hash crash with shash
Recently algif_hash has been changed to allow null hashes. This
triggers a bug when used with an shash algorithm whereby it will
cause a crash during the digest operation.
This patch fixes it by avoiding the digest operation and instead
doing an init followed by a final which avoids the buggy code in
shash.
This patch also ensures that the result buffer is freed after an
error so that it is not returned as a genuine hash result on the
next recv call.
The shash/ahash wrapper code will be fixed later to handle this
case correctly.
Fixes: 493b2ed3f760 ("crypto: algif_hash - Handle NULL hashes correctly")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Laura Abbott <labbott@redhat.com>
Diffstat (limited to 'crypto')
-rw-r--r-- | crypto/algif_hash.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c index 2d8466f9e49b..05e21b464433 100644 --- a/crypto/algif_hash.c +++ b/crypto/algif_hash.c @@ -214,23 +214,26 @@ static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0); - if (ctx->more) { + if (!result) { + err = af_alg_wait_for_completion( + crypto_ahash_init(&ctx->req), + &ctx->completion); + if (err) + goto unlock; + } + + if (!result || ctx->more) { ctx->more = 0; err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req), &ctx->completion); if (err) goto unlock; - } else if (!result) { - err = af_alg_wait_for_completion( - crypto_ahash_digest(&ctx->req), - &ctx->completion); } err = memcpy_to_msg(msg, ctx->result, len); - hash_free_result(sk, ctx); - unlock: + hash_free_result(sk, ctx); release_sock(sk); return err ?: len; |