In Linux kernel 8250 serial drivers, a missing FIFO error interrupt handler can cause the ISR to repeatedly trigger, keeping the processor in a busy‑wait state. The kernel returns IRQ_HANDLED without clearing the FIFO error status, which re‑fires the IRQ and leads to a soft lockup. The resulting CPU is stuck in the ISR, making all processes unresponsive until a reboot. The flaw is reflected by CWE‑835 (Infinite Loop).

The vulnerability occurs in any Linux kernel that includes the 8250 serial driver, including the specialised OMAP 8250 driver used on AM62L hardware. No explicit kernel version is cited, so any kernel prior to the commit that introduced FIFO error handling (identified by commit 0c6bf45e5a345cc3b9ffbeaf9083ecac3c2293eb) remains susceptible.

With a CVSS score of 5.5 the severity is moderate, and the EPSS score of < 1 % indicates a very low probability that the flaw is currently being exploited. The vulnerability is not listed in the CISA KEV catalog, so no publicly known exploits exist. Based on the description, it is inferred that the likely attack vector requires an attacker to send a burst of serial traffic during system boot or to have local access to the serial port, causing the FIFO error and triggering the ISR loop. Such an attack would result in a denial of service, forcing a system reboot to restore normal operation.