tcp: fix req->saved_syn race

For the reasons explained in commit ce1050089c ("tcp/dccp: fix
ireq->pktopts race"), we need to make sure we do not access
req->saved_syn unless we own the request sock.

This fixes races for listeners using TCP_SAVE_SYN option.

Fixes: e994b2f0fb ("tcp: do not lock listener to process SYN packets")
Fixes: 079096f103 ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Ying Cai <ycai@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2015-11-05 11:07:13 -08:00
committed by David S. Miller
parent 428ad1bc6d
commit 805c4bc057
4 changed files with 21 additions and 11 deletions

View File

@@ -551,9 +551,6 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
newtp->rack.mstamp.v64 = 0;
newtp->rack.advanced = 0;
newtp->saved_syn = req->saved_syn;
req->saved_syn = NULL;
TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_PASSIVEOPENS);
}
return newsk;