path: root/crypto
diff options
authorEric Biggers <ebiggers@google.com>2017-11-27 23:23:05 -0800
committerHerbert Xu <herbert@gondor.apana.org.au>2017-11-29 13:39:14 +1100
commitb32a7dc8aef1882fbf983eb354837488cc9d54dc (patch)
treeaa8d50f168a77514cf9f32ac98b179a0741b8fe4 /crypto
parentd2890c3778b164fde587bc16583f3a1c87233ec5 (diff)
crypto: algif_aead - fix reference counting of null skcipher
In the AEAD interface for AF_ALG, the reference to the "null skcipher" held by each tfm was being dropped in the wrong place -- when each af_alg_ctx was freed instead of when the aead_tfm was freed. As discovered by syzkaller, a specially crafted program could use this to cause the null skcipher to be freed while it is still in use. Fix it by dropping the reference in the right place. Fixes: 72548b093ee3 ("crypto: algif_aead - copy AAD from src to dst") Reported-by: syzbot <syzkaller@googlegroups.com> Cc: <stable@vger.kernel.org> # v4.14+ Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
1 files changed, 1 insertions, 1 deletions
diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c
index aacae0837aff..9d73be28cf01 100644
--- a/crypto/algif_aead.c
+++ b/crypto/algif_aead.c
@@ -487,6 +487,7 @@ static void aead_release(void *private)
struct aead_tfm *tfm = private;
+ crypto_put_default_null_skcipher2();
@@ -519,7 +520,6 @@ static void aead_sock_destruct(struct sock *sk)
unsigned int ivlen = crypto_aead_ivsize(tfm);
af_alg_pull_tsgl(sk, ctx->used, NULL, 0);
- crypto_put_default_null_skcipher2();
sock_kzfree_s(sk, ctx->iv, ivlen);
sock_kfree_s(sk, ctx, ctx->len);