Resource Management Flaw in Linux Kernel Affects Network Communication

CVE-2026-31640

What is CVE-2026-31640?

A vulnerability present in the Linux kernel impacts the response handling of the RxRPC protocol. The flaw arises from an incorrect comparison of the challenge serial number in the rxrpc_post_response() function. Instead of correctly utilizing the cached response's challenge serial, the code erroneously uses the data from a newer packet, which leads to consistent false comparisons. This defect not only hinders proper decision making but may also allow attackers to exploit the response handling mechanism. Remediation involves switching the focus back to the older packet for accurate comparisons and ensuring that unused packets are properly managed.

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