mptcp: fix possible stall on recvmsg()
This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v5.15 by commit 612f71d7328c14369924384ad2170aae2a6abd92, it was introduced in version v5.6 by commit 7a6a6cbc3e592e339ad23e4e8ede9a3f6160bda8. For more details please see the references link.