[PATCH 4.4 082/117] crypto: af_alg - Fix socket double-free when accept fails

Greg Kroah-Hartman
2016-02-15T00:28:44Z

From: Herbert Xu <herbert@gondor.apana.org.au>

commit a383292c86663bbc31ac62cc0c04fc77504636a6 upstream.

When we fail an accept(2) call we will end up freeing the socket
twice, once due to the direct sk_free call and once again through
newsock.

This patch fixes this by removing the sk_free call.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
crypto/af_alg.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -285,10 +285,8 @@ int af_alg_accept(struct sock *sk, struc
security_sk_clone(sk, sk2);

err = type->accept(ask->private, sk2);
- if (err) {
- sk_free(sk2);
+ if (err)
goto unlock;
- }

sk2->sk_family = PF_ALG;