• Christoph Paasch's avatar
    tcp md5sig: Use skb's saddr when replying to an incoming segment · 30791ac4
    Christoph Paasch authored
    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: 9501f972 ("tcp md5sig: Let the caller pass appropriate key for tcp_v{4,6}_do_calc_md5_hash().")
    Signed-off-by: default avatarChristoph Paasch <cpaasch@apple.com>
    Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    30791ac4
tcp_ipv4.c 66.3 KB