tcp md5sig: Use skb's saddr when replying to an incoming segment

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The MD5-key that belongs to a connection is identified by the peer's
IP-address. When we are in tcp_v4(6)_reqsk_send_ack(), we are replying
to an incoming segment from tcp_check_req() that failed the seq-number
checks.

Thus, to find the correct key, we need to use the skb's saddr and not
the daddr.

This bug seems to have been there since quite a while, but probably got
unnoticed because the consequences are not catastrophic. We will call
tcp_v4_reqsk_send_ack only to send a challenge-ACK back to the peer,
thus the connection doesn't really fail.

Fixes: 9501f97229 ("tcp md5sig: Let the caller pass appropriate key for tcp_v{4,6}_do_calc_md5_hash().")
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

...

This commit is contained in:

Christoph Paasch 2017-12-11 00:05:46 -08:00 • committed by David S. Miller

parent 200809716a

commit 30791ac419

2 changed files with 2 additions and 2 deletions

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2

net/ipv4/tcp_ipv4.c

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2

net/ipv6/tcp_ipv6.c

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