CVE-2025-38552

Critical

Description

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.

SeverityCritical
CVSS9.4
Exploit probability—
ProductLinux Kernel
PublishedAug 16, 2025
First seenAug 16, 2025

How to fix

Update
  • linux linux_kernel6.1.149, 6.6.101, 6.12.40, 6.15.8 or later

Affected products

ProductAffected versionsFixed in
linux linux_kernel5.15 ≤ v < 6.1.149, 6.2 ≤ v < 6.6.101, 6.7 ≤ v < 6.12.40, 6.13 ≤ v < 6.15.8, 6.166.1.149, 6.6.101, 6.12.40, 6.15.8
debian debian_linux11.0—

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