mptcp: fix NULL ptr dereference in MP_JOIN error path
When token lookup on MP_JOIN 3rd ack fails, the server
socket closes with a reset the incoming child. Such socket
has the 'is_mptcp' flag set, but no msk socket associated
- due to the failed lookup.
While crafting the reset packet mptcp_established_options_mp()
will try to dereference the child's master socket, causing
a NULL ptr dereference.
This change addresses the issue with explicit fallback to
TCP in such error path.
Fixes: 729cd6436f35 ("mptcp: cope better with MP_JOIN failure")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed