From: Vasily Averin <v...@parallels.com>

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

===============

[ Upstream commit 4062090e3e5caaf55bed4523a69f26c3265cc1d2 ]

ip_setup_cork() called inside ip_append_data() steals dst entry from rt to cork
and in case errors in __ip_append_data() nobody frees stolen dst entry

Fixes: 2e77d89b2fa8 ("net: avoid a pair of dst_hold()/dst_release() in 
ip_append_data()")
Signed-off-by: Vasily Averin <v...@parallels.com>
Acked-by: Eric Dumazet <eduma...@google.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
---
 net/ipv4/ip_output.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index c1cb9475fadf..c2dcee28d071 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1478,6 +1478,7 @@ void ip_send_unicast_reply(struct net *net, struct 
sk_buff *skb, __be32 daddr,
        struct sk_buff *nskb;
        struct sock *sk;
        struct inet_sock *inet;
+       int err;
 
        if (ip_options_echo(&replyopts.opt.opt, skb))
                return;
@@ -1514,8 +1515,13 @@ void ip_send_unicast_reply(struct net *net, struct 
sk_buff *skb, __be32 daddr,
        sock_net_set(sk, net);
        __skb_queue_head_init(&sk->sk_write_queue);
        sk->sk_sndbuf = sysctl_wmem_default;
-       ip_append_data(sk, &fl4, ip_reply_glue_bits, arg->iov->iov_base, len, 0,
-                      &ipc, &rt, MSG_DONTWAIT);
+       err = ip_append_data(sk, &fl4, ip_reply_glue_bits, arg->iov->iov_base,
+                            len, 0, &ipc, &rt, MSG_DONTWAIT);
+       if (unlikely(err)) {
+               ip_flush_pending_frames(sk);
+               goto out;
+       }
+
        nskb = skb_peek(&sk->sk_write_queue);
        if (nskb) {
                if (arg->csumoffset >= 0)
@@ -1527,7 +1533,7 @@ void ip_send_unicast_reply(struct net *net, struct 
sk_buff *skb, __be32 daddr,
                skb_set_queue_mapping(nskb, skb_get_queue_mapping(skb));
                ip_push_pending_frames(sk, &fl4);
        }
-
+out:
        put_cpu_var(unicast_sock);
 
        ip_rt_put(rt);
-- 
2.1.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to