The mentioned issues is fixed by any of this 2 patches.

The first one is a minimal fix that could land to stable,
the second one addresses the an underlaying state-management
bug, which needs some more complex changes.

The plan is to send them both to -net.

Paolo Abeni (2):
  mptcp: more strict state checking for acks
  mptcp: better msk-level shutdown.

 net/mptcp/protocol.c | 64 +++++++++++++-------------------------------
 1 file changed, 18 insertions(+), 46 deletions(-)

-- 
2.26.2