CVE-2025-38552
CriticalCVSS 9.4Exploitation Probability (EPSS)
Low risk23th percentile - higher than 23% of all known CVEs
Summary
In the Linux kernel MPTCP stack, races between subflow failure and new subflow creation are fixed by adding a separate flag protected by the fallback lock, preventing additional subflow creation in certain socket states.
Risk Assessment
Races could lead to unexpected MPTCP connection behavior, potentially allowing an attacker to destabilize connections or compromise data integrity.
Recommendation
Update the Linux kernel to a version containing the patch that introduces a flag protected by the fallback lock for states preventing additional subflow creation.
Original NVD description (English source)
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.