CVE-2023-54263: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-54263 is a vulnerability in the Linux kernel's DRM/Nouveau graphics driver subsystem, specifically in the KMS (Kernel Mode Setting) component for nv50 and later NVIDIA GPU generations. The flaw involves a failure to initialize the hpd_irq_lock mutex for PIOR (Programmable I/O Resource) DisplayPort connections, causing an OOPS (kernel panic/crash) on systems with ANX9805 DP encoders. It was published on December 30, 2025, and affects Linux kernel versions from the initial commit up to (but not including) commits 92d48ce21645267c574268678131cd2b648dad0f (patched in 6.5) and ea293f823a8805735d9e00124df81a8f448ed1ae (patched in 6.4.7). The CVSS base score is not formally assigned (estimated Medium by Feedly), and the EPSS score is approximately 0.024% (Feedly, EUVD).

The root cause is an uninitialized mutex (hpd_irq_lock) in the Nouveau DRM driver's PIOR DisplayPort handling code (CWE-908: Use of Uninitialized Resource). When a system with an ANX9805 external DisplayPort encoder is present, the kernel attempts to use this lock before it has been properly initialized via spin_lock_init() or equivalent, resulting in a kernel OOPS. The fix, applied in Linux 6.4.7 and 6.5, adds the missing initialization call for the hpd_irq_lock in the PIOR DP code path (Feedly, EUVD). The patches are available at the upstream stable kernel repository (Kernel Git 6.5, Kernel Git 6.4.7).

Exploitation of this vulnerability results in a kernel OOPS (crash) on affected Linux systems equipped with NVIDIA GPUs using the Nouveau driver and ANX9805 external DisplayPort encoders. The primary impact is a denial of service — the system may become unresponsive or require a reboot. There is no known confidentiality or integrity impact, and the vulnerability is limited to systems with the specific hardware configuration (ANX9805 DP encoder) (Feedly, EUVD).

The fix is included in Linux kernel versions 6.4.7 and 6.5. Users running affected kernel versions on systems with ANX9805 DisplayPort encoders should upgrade to Linux kernel 6.4.7 or later (stable branch), or 6.5 or later. As a workaround, users may avoid using the Nouveau driver on affected hardware by switching to the proprietary NVIDIA driver or disabling the affected display output, though upgrading the kernel is the recommended solution (Kernel Git 6.5, Kernel Git 6.4.7).