From: Greg KH <[email protected]> 3.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Eric Dumazet <[email protected]> [ Upstream commit 4399a4df98a63e30fd16e9d0cecc46ea92269e8f ] 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 <[email protected]> Cc: James Chapman <[email protected]> Cc: Denys Fedoryshchenko <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- net/l2tp/l2tp_ip.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -516,10 +516,12 @@ static int l2tp_ip_sendmsg(struct kiocb 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. @@ -527,6 +529,7 @@ static int l2tp_ip_sendmsg(struct kiocb */ 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(); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
