Message ID | 20130411000909.d90c6df468bf1830174e88e2@highloadlab.com |
---|---|
State | Changes Requested, archived |
Delegated to: | David Miller |
Headers | show |
From: Dmitry Popov <dp@highloadlab.com> Date: Thu, 11 Apr 2013 00:09:09 +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 in new socket (get_cookie_sock -> tcp_v4_syn_recv_sock), so its packets may take wrong path. There is no such bug in ipv6 code and non-cookie code (usual case). Bugfix below. > > Signed-off-by: Dmitry Popov <dp@highloadlab.com> Please format your commit messages properly, by not allowing lines of text longer than 80 columns. Thank you. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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);
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 in new socket (get_cookie_sock -> tcp_v4_syn_recv_sock), so its packets may take wrong path. There is no such bug in ipv6 code and non-cookie code (usual case). Bugfix below. Signed-off-by: Dmitry Popov <dp@highloadlab.com> --- net/ipv4/syncookies.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html