This is a note to let you know that I've just added the patch titled tcp: incoming connections might use wrong route under synflood to the 3.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tcp-incoming-connections-might-use-wrong-route-under-synflood.patch and it can be found in the queue-3.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 7293e360700498d14aa0530071fc29819f242e74 Mon Sep 17 00:00:00 2001 From: Dmitry Popov <dp@xxxxxxxxxxxxxxx> Date: Thu, 11 Apr 2013 08:55:07 +0000 Subject: tcp: incoming connections might use wrong route under synflood From: Dmitry Popov <dp@xxxxxxxxxxxxxxx> [ Upstream commit d66954a066158781ccf9c13c91d0316970fe57b6 ] There is a bug in cookie_v4_check (net/ipv4/syncookies.c): flowi4_init_output(&fl4, 0, sk->sk_mark, RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, IPPROTO_TCP, inet_sk_flowi_flags(sk), (opt && opt->srr) ? opt->faddr : ireq->rmt_addr, ireq->loc_addr, th->source, th->dest); Here we do not respect sk->sk_bound_dev_if, therefore wrong dst_entry may be taken. This dst_entry is used by new socket (get_cookie_sock -> tcp_v4_syn_recv_sock), so its packets may take the wrong path. Signed-off-by: Dmitry Popov <dp@xxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv4/syncookies.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -345,8 +345,8 @@ struct sock *cookie_v4_check(struct sock * hasn't changed since we received the original syn, but I see * no easy way to do this. */ - flowi4_init_output(&fl4, 0, sk->sk_mark, RT_CONN_FLAGS(sk), - RT_SCOPE_UNIVERSE, IPPROTO_TCP, + flowi4_init_output(&fl4, sk->sk_bound_dev_if, sk->sk_mark, + RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, IPPROTO_TCP, inet_sk_flowi_flags(sk), (opt && opt->srr) ? opt->faddr : ireq->rmt_addr, ireq->loc_addr, th->source, th->dest); Patches currently in stable-queue which might be from dp@xxxxxxxxxxxxxxx are queue-3.0/tcp-incoming-connections-might-use-wrong-route-under-synflood.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html