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

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Date:	Sun, 14 Feb 2016 14:21:59 -0800
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org, Dmitry Vyukov <dvyukov@...gle.com>,
	Herbert Xu <herbert@...dor.apana.org.au>
Subject: [PATCH 4.4 082/117] crypto: af_alg - Fix socket double-free when accept fails

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Herbert Xu <herbert@...dor.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@...gle.com>
Signed-off-by: Herbert Xu <herbert@...dor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.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;