In the Linux kernel, the following vulnerability has been resolved: mptcp: plug races between subflow fail and subflow creation We have races similar to the one addressed by the previous patch between subflow failing and additional subflow creation. They are just harder to trigger. The solution is similar. Use a separate flag to track the condition 'socket state prevent any additional subflow creation' protected by the fallback lock. The socket fallback makes such flag true, and also receiving or sending an MP_FAIL option. The field 'allow_infinite_fallback' is now always touched under the relevant lock, we can drop the ONCE annotation on write.
https://git.kernel.org/stable/c/f81b6fbe13c7fc413b5158cdffc6a59391a2a8db
https://git.kernel.org/stable/c/def5b7b2643ebba696fc60ddf675dca13f073486
https://git.kernel.org/stable/c/7c96d519ee15a130842a6513530b4d20acd2bfcd
https://git.kernel.org/stable/c/659da22dee5ff316ba63bdaeeac7b58b5442f6c2