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| author | Eric Dumazet <edumazet@google.com> | 2012-06-08 06:25:00 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-06-08 14:30:51 -0700 |
| commit | 4399a4df98a63e30fd16e9d0cecc46ea92269e8f (patch) | |
| tree | 6068b48be8fe07b2501a849b152436c42106650d | |
| parent | 6a2b28ef036ab5c66fdc606fe97d9e5cb34ea409 (diff) | |
| download | linux-4399a4df98a63e30fd16e9d0cecc46ea92269e8f.tar.gz linux-4399a4df98a63e30fd16e9d0cecc46ea92269e8f.tar.bz2 linux-4399a4df98a63e30fd16e9d0cecc46ea92269e8f.zip | |
l2tp: fix a race in l2tp_ip_sendmsg()
Commit 081b1b1bb27f (l2tp: fix l2tp_ip_sendmsg() route handling) added
a race, in case IP route cache is disabled.
In this case, we should not do the dst_release(&rt->dst), since it'll
free the dst immediately, instead of waiting a RCU grace period.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Cc: Denys Fedoryshchenko <denys@visp.net.lb>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/l2tp/l2tp_ip.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c index 70614e7affab..61d8b75d2686 100644 --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -464,10 +464,12 @@ static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *m sk->sk_bound_dev_if); if (IS_ERR(rt)) goto no_route; - if (connected) + if (connected) { sk_setup_caps(sk, &rt->dst); - else - dst_release(&rt->dst); /* safe since we hold rcu_read_lock */ + } else { + skb_dst_set(skb, &rt->dst); + goto xmit; + } } /* We dont need to clone dst here, it is guaranteed to not disappear. @@ -475,6 +477,7 @@ static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *m */ skb_dst_set_noref(skb, &rt->dst); +xmit: /* Queue the packet to IP for output */ rc = ip_queue_xmit(skb, &inet->cork.fl); rcu_read_unlock(); |