CVE-2026-98883: serial: 8250_port: recognize UPIO_AU

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-23 · updated 2026-10-26

Description

In the Linux kernel, the following vulnerability has been resolved: serial: 8250_port: recognize UPIO_AU My MIPS Alchemy systems generate the following warning during probe of the 8250 driver: WARNING: drivers/tty/serial/8250/8250_port.c:462 at set_io_from_upio+0xfc/0x124, CPU#0: swapper/0/1 Unsupported UART type 4 [...] [<80521d40>] set_io_from_upio+0xfc/0x124 [<80521dfc>] serial8250_set_defaults+0x94/0xe0 [<80520fb4>] serial8250_register_8250_port+0x288/0x51c [<805214ec>] serial8250_probe+0x160/0x1e8 [<8053b5f0>] platform_probe+0x64/0x90 The least invasive fix is to recognize UPIO_AU (type 4) in set_io_from_upio() and do nothing, since all parameters have already been set up in 8250_rt288x.c::au_platform_setup(). Run-tested on Alchemy Au1300 platform.

Affected products

Linux kernel: before 6.18.53 — fixed in 6.18.53, 7.2

How to fix

Upgrade to a fixed version: Linux kernel 6.18.53, 7.2. Check the vendor advisory for mitigations.

References

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