mptcp: drop MP_JOIN request sock on syn cookies
authorPaolo Abeni <pabeni@redhat.com>
Wed, 17 Jun 2020 10:08:57 +0000 (12:08 +0200)
committerDavid S. Miller <davem@davemloft.net>
Fri, 19 Jun 2020 03:25:51 +0000 (20:25 -0700)
commit9e365ff576b7c1623bbc5ef31ec652c533e2f65e
tree5acc4e5efb1b182ea58308c74024884dbfe05860
parent8fd4de1275580a1befa1456d1070eaf6489fb48f
mptcp: drop MP_JOIN request sock on syn cookies

Currently any MPTCP socket using syn cookies will fallback to
TCP at 3rd ack time. In case of MP_JOIN requests, the RFC mandate
closing the child and sockets, but the existing error paths
do not handle the syncookie scenario correctly.

Address the issue always forcing the child shutdown in case of
MP_JOIN fallback.

Fixes: ae2dd7164943 ("mptcp: handle tcp fallback when using syn cookies")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/mptcp/subflow.c