* [PATCH RESEND] tcp: incoming connections might use wrong route under synflood
@ 2013-04-11 18:55 Dmitry Popov
2013-04-11 20:02 ` David Miller
0 siblings, 1 reply; 2+ messages in thread
From: Dmitry Popov @ 2013-04-11 18:55 UTC (permalink / raw)
To: David S. Miller, Alexey Kuznetsov, James Morris,
Hideaki YOSHIFUJI, Patrick McHardy
Cc: netdev, linux-kernel
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@highloadlab.com>
---
net/ipv4/syncookies.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index ef54377..397e0f6 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -349,8 +349,8 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
* 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);
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH RESEND] tcp: incoming connections might use wrong route under synflood
2013-04-11 18:55 [PATCH RESEND] tcp: incoming connections might use wrong route under synflood Dmitry Popov
@ 2013-04-11 20:02 ` David Miller
0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2013-04-11 20:02 UTC (permalink / raw)
To: dp; +Cc: kuznet, jmorris, yoshfuji, kaber, netdev, linux-kernel
From: Dmitry Popov <dp@highloadlab.com>
Date: Thu, 11 Apr 2013 22:55:07 +0400
> 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@highloadlab.com>
Applied.
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2013-04-11 20:02 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-04-11 18:55 [PATCH RESEND] tcp: incoming connections might use wrong route under synflood Dmitry Popov
2013-04-11 20:02 ` David Miller
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).