CVE-2023-54131: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-54131 is a memory leak vulnerability in the Linux kernel's rt2x00 Wi-Fi driver that can result in a Denial of Service condition. When a rt2x00 device is removed, its associated channel surveys are not freed, causing a persistent memory leak detectable via kmemleak. The vulnerability affects the Linux kernel and was publicly disclosed on December 24, 2025. It carries a CVSS v3.1 base score of 7.0 (High) (Red Hat Advisory, Red Hat Bugzilla).

The root cause is a missing memory deallocation (CWE-401: Missing Release of Memory after Effective Lifetime) in the rt2x00 Wi-Fi driver subsystem of the Linux kernel. During device probe, rt2800_probe_hw() allocates memory for channel surveys via __kmalloc, but this memory is never freed when the device is subsequently removed. The leak is local in nature, requiring low-privileged access, and is triggered by the device removal lifecycle (e.g., unplugging a USB wireless adapter such as a RT3070-based device). The issue was confirmed and observed via kmemleak output showing unreferenced 512-byte objects allocated during systemd-udevd device handling (Red Hat Bugzilla).

Successful exploitation leads to a gradual memory exhaustion on the affected system, ultimately causing a Denial of Service condition. Because memory is leaked each time a rt2x00 device is removed and re-inserted, repeated plug/unplug cycles can accelerate memory depletion. The CVSS score also reflects potential high impacts on confidentiality and integrity (score 7.0), though the primary practical impact is availability degradation on Linux systems using rt2x00-based Wi-Fi adapters (Red Hat Advisory, Red Hat Bugzilla).

The fix involves freeing channel surveys during device removal in the rt2x00 driver. Upstream kernel patches have been committed to the stable kernel tree (commits 0354bce76ed1, 494064ffd60d, bea3f8aa9993, and cbef9a83c51d). Users should update to a patched Linux kernel version that includes these fixes. Red Hat has tracked this issue in Bugzilla (Bug 2425120) and users of affected Red Hat products should monitor for updated kernel packages. As a workaround, avoiding frequent plug/unplug cycles of rt2x00-based USB Wi-Fi adapters can reduce the rate of memory leakage (Red Hat Bugzilla).