Race Condition in MultiPath TCP Implementation of Linux Kernel

CVE-2025-40257

What is CVE-2025-40257?

A vulnerability in the Linux Kernel's MultiPath TCP (MPTCP) component could lead to a race condition during timer management. The function handling timer deletions, 'mptcp_pm_del_add_timer', may interact incorrectly with other processes, potentially leading to a use-after-free scenario. This could result in unpredictable behavior or crashes. The issue has been addressed by implementing RCU protection and clarifying variable names for better code readability. Users are encouraged to update their systems to incorporate these security improvements.

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