In arm32 and arm64 Linux kernels that employ the AMBA PL011 UART console, the driver invoked clk_enable() while in a non‑preemptible atomic context during atomic printk calls or NMI write_atomic() operations. The common‑clock enable lock can sleep in PREEMPT_RT builds, and when a sleeping routine is called from an atomic context a kernel BUG is triggered, causing a kernel panic and rendering the system unusable. The flaw does not provide a direct attacker control path; its effect is limited to a local fault condition that results in denial of service.

The vulnerability affects all ARM 32‑bit and ARM 64‑bit System‑on‑Chip platforms that use the PL011 UART console driver in the Linux kernel. Any kernel build that mixes the PL011 console with a reclaimable clock source—commonly found in many embedded and IoT SoCs—falls under the impact scope.

The EPSS value is less than 1 %, and the vulnerability is not listed in CISA’s KEV catalog, indicating a very low likelihood of observed exploitation. An attacker would need local kernel execution or the ability to trigger atomic printk or NMI context writes to the console. The issue is primarily a robustness bug that can be triggered by normal system activity, but it does not provide a vector for code execution or privilege escalation.