tcp: tcp_replace_ts_recent() should not be called from tcp_validate_incoming()

We added support for RFC 5961 in latest kernels but TCP fails
to perform exhaustive check of ACK sequence.

We can update our view of peer tsval from a frame that is
later discarded by tcp_ack()

This makes timestamps enabled sessions vulnerable to injection of
a high tsval : peers start an ACK storm, since the victim
sends a dupack each time it receives an ACK from the other peer.

As tcp_validate_incoming() is called before tcp_ack(), we should
not peform tcp_replace_ts_recent() from it, and let callers do it
at the right time.

Signed-off-by: Eric Dumazet <[email protected]>
Cc: Neal Cardwell <[email protected]>
Cc: Yuchung Cheng <[email protected]>
Cc: Nandita Dukkipati <[email protected]>
Cc: H.K. Jerry Chu <[email protected]>
Cc: Romain Francoise <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions