CVE-2024-53123

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 6.6.65

Description A division by zero error was reported in the MPTCP protocol of the Linux kernel. The root cause is the current bad handling of racing disconnect. After a specific commit, sk wait data() can return with an error and the underlying socket disconnected, resulting in a zero rcv mss. The error occurs when tcp select window() is called, leading to a divide error. The issue is resolved by catching the error and returning without performing any additional operations on the current socket.

Recommendations To resolve the issue, update the Linux kernel to version 6.6.65 or later. As a temporary workaround, consider disabling the mptcp recvmsg() function until a patch is available. Restrict access to the vulnerable mptcp protocol to minimize the risk of exploitation. Avoid using the rcv mss variable in the affected API endpoint until the issue is resolved.