From 4062090e3e5caaf55bed4523a69f26c3265cc1d2 Mon Sep 17 00:00:00 2001 From: Vasily Averin Date: Wed, 15 Oct 2014 16:24:02 +0400 Subject: [PATCH] ipv4: dst_entry leak in ip_send_unicast_reply() 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 Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- 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 e35b71289156..88e5ef2c7f51 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1535,6 +1535,7 @@ void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, struct sk_buff *nskb; struct sock *sk; struct inet_sock *inet; + int err; if (__ip_options_echo(&replyopts.opt.opt, skb, sopt)) return; @@ -1574,8 +1575,13 @@ void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, 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) @@ -1587,7 +1593,7 @@ void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, 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); -- 2.39.2