[PATCH 4.14 13/52] tcp: remove buggy call to tcp_v6_restore_cb()

From: Greg Kroah-Hartman
Date: Fri Dec 15 2017 - 04:53:54 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@xxxxxxxxxx>


[ Upstream commit 3016dad75b48279e579117ee3ed566ba90a3b023 ]

tcp_v6_send_reset() expects to receive an skb with skb->cb[] layout as
used in TCP stack.
MD5 lookup uses tcp_v6_iif() and tcp_v6_sdif() and thus
TCP_SKB_CB(skb)->header.h6

This patch probably fixes RST packets sent on behalf of a timewait md5
ipv6 socket.

Before Florian patch, tcp_v6_restore_cb() was needed before jumping to
no_tcp_socket label.

Fixes: 271c3b9b7bda ("tcp: honour SO_BINDTODEVICE for TW_RST case too")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Florian Westphal <fw@xxxxxxxxx>
Acked-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv6/tcp_ipv6.c | 1 -
1 file changed, 1 deletion(-)

--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1585,7 +1585,6 @@ do_time_wait:
tcp_v6_timewait_ack(sk, skb);
break;
case TCP_TW_RST:
- tcp_v6_restore_cb(skb);
tcp_v6_send_reset(sk, skb);
inet_twsk_deschedule_put(inet_twsk(sk));
goto discard_it;