tcp: fix crash in tcp_xmit_retransmit_queue
authorIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Mon, 19 Jul 2010 01:16:18 +0000 (01:16 +0000)
committerDavid S. Miller <davem@davemloft.net>
Mon, 19 Jul 2010 19:43:49 +0000 (12:43 -0700)
commit45e77d314585869dfe43c82679f7e08c9b35b898
tree73c6322600e47a44a8c171abff392a61eac53be9
parentb508998f665ee6d6a15eae11be258c3e94c33562
tcp: fix crash in tcp_xmit_retransmit_queue

It can happen that there are no packets in queue while calling
tcp_xmit_retransmit_queue(). tcp_write_queue_head() then returns
NULL and that gets deref'ed to get sacked into a local var.

There is no work to do if no packets are outstanding so we just
exit early.

This oops was introduced by 08ebd1721ab8fd (tcp: remove tp->lost_out
guard to make joining diff nicer).

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Reported-by: Lennart Schulte <lennart.schulte@nets.rwth-aachen.de>
Tested-by: Lennart Schulte <lennart.schulte@nets.rwth-aachen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/tcp_output.c