From: Eric Dumazet <edumazet@google.com>
Date: Fri, 17 May 2013 04:53:13 +0000 (+0000)
Subject: ipv6: fix possible crashes in ip6_cork_release()
X-Git-Tag: v3.10-rc3~18^2~31
X-Git-Url: http://pileus.org/git/?a=commitdiff_plain;ds=sidebyside;h=284041ef21fdf2e0d216ab6b787bc9072b4eb58a;p=~andy%2Flinux

ipv6: fix possible crashes in ip6_cork_release()

commit 0178b695fd6b4 ("ipv6: Copy cork options in ip6_append_data")
added some code duplication and bad error recovery, leading to potential
crash in ip6_cork_release() as kfree() could be called with garbage.

use kzalloc() to make sure this wont happen.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Neal Cardwell <ncardwell@google.com>
---

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index d2eedf19233..dae1949019d 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1147,7 +1147,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
 			if (WARN_ON(np->cork.opt))
 				return -EINVAL;
 
-			np->cork.opt = kmalloc(opt->tot_len, sk->sk_allocation);
+			np->cork.opt = kzalloc(opt->tot_len, sk->sk_allocation);
 			if (unlikely(np->cork.opt == NULL))
 				return -ENOBUFS;