In the Linux kernel, the following vulnerability has been resolved: serial: 8250_port: recognize UPIO_AU My MIPS Alchemy systems generate the… (CVE-2026-98883)

The Linux kernel's 8250 serial driver did not recognize the UPIO_AU (type 4) UART type on MIPS Alchemy systems, leading to warnings during driver probe. The vulnerability was addressed by updating the set_io_from_upio() function to recognize UPIO_AU and perform no further action, as the necessary parameters are already configured in the au_platform_setup() function of 8250_rt288x.c. This change prevents the warning and ensures proper driver initialization on affected hardware. The fix has been run-tested on the Alchemy Au1300 platform.

The vulnerability caused warnings during the initialization of the 8250 serial driver on specific MIPS Alchemy hardware, which could potentially affect system stability or driver behavior. No direct exploit or security impact is described. The fix prevents these warnings by properly recognizing the UART type, improving system reliability on affected platforms.

A fix is available that updates the Linux kernel 8250 serial driver to recognize UPIO_AU (type 4) UARTs correctly. Users should apply the updated kernel version containing this fix. No additional mitigation steps are necessary as the issue is resolved by this patch.