This address the issue the easy way: removing the bugged features
(a lot of setsockopt including all mcast related).

As suggested by Mat(s) this switch to a whitelist. Assembling the
whilelist itself is quite complex/tedious/errorprone so still RFC.

Please have a look at 1/2 for the details

Paolo Abeni (2):
  mptcp: only admit explicitly supported sockopt
  mptcp: revert "mptcp: provide subflow aware release function"$ ....$

 net/mptcp/protocol.c | 270 ++++++++++++++++++++++++++++++++++---------
 1 file changed, 217 insertions(+), 53 deletions(-)

-- 
2.26.2