From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Wed, 30 Dec 2015 12:24:17 +0000 (+0800)
Subject: crypto: af_alg - Fix socket double-free when accept fails
X-Git-Tag: firefly_0821_release~3391^2~38
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=aa435a11e4bb37e23dbfc45fea2c11ddf6b813e0;p=firefly-linux-kernel-4.4.55.git

crypto: af_alg - Fix socket double-free when accept fails

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>
---

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 7b5b5926c767..eaf98e287d89 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -285,10 +285,8 @@ int af_alg_accept(struct sock *sk, struct socket *newsock)
 	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;