Messages in this thread | | | Date | Wed, 10 Apr 2013 23:26:12 -0400 (EDT) | Subject | Re: [PATCH] tcp: incoming connections might use wrong route under synflood | From | David Miller <> |
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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.
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