From: Vasily Averin <vvs@parallels•com>
To: Eric Dumazet <eric.dumazet@gmail•com>,
netdev@vger•kernel.org, "David S. Miller" <davem@davemloft•net>
Cc: Alexey Kuznetsov <kuznet@ms2•inr.ac.ru>,
James Morris <jmorris@namei•org>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6•org>,
Patrick McHardy <kaber@trash•net>
Subject: [PATCH] ipv4: dst_entry leak in ip_send_unicast_reply()
Date: Wed, 15 Oct 2014 16:24:02 +0400 [thread overview]
Message-ID: <543E6762.9090807@parallels.com> (raw)
Fixes: 2e77d89b2fa8 ("net: avoid a pair of dst_hold()/dst_release() in ip_append_data()")
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
Signed-off-by: Vasily Averin <vvs@parallels•com>
---
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 e35b712..88e5ef2 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);
--
1.9.1
next reply other threads:[~2014-10-15 12:25 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-15 12:24 Vasily Averin [this message]
2014-10-17 15:59 ` [PATCH] ipv4: dst_entry leak in ip_send_unicast_reply() David Miller
2014-10-17 16:56 ` Eric Dumazet
2014-10-17 19:30 ` David Miller
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