In the Linux kernel, an invoke of fastrpc can be interrupted by a signal, causing the internal function to move buffers from a file’s mmap list to an "interrupted" list. This transfer runs without acquiring the lock that normally protects the mmap list. The missing lock introduces a race condition that can corrupt kernel memory or enable an attacker to manipulate the list of memory mappings. The result could allow escalation of privileges or arbitrary code execution once the corrupted memory is used.

All Linux kernel releases that include the fastrpc subsystem before the commit that introduces the missing lock fix are potentially affected. The vulnerability is tied to the generic Linux kernel and therefore applies to any distribution that ships the affected kernel version without the patch.

The vulnerability is a classic race condition (CWE‑362). No EPSS score is available and it is not listed in CISA’s KEV catalog, indicating no known public exploits at the time of analysis. However, the absence of a synchronisation lock means the race could be triggered by an attacker with local or, where fastrpc exposes a remote interface, remote code. The severity is high due to the kernel context and potential for arbitrary code execution; a local attacker could exploit it, and a remote attacker could do so if the fastrpc interface is exposed.