CVE-2026-98883

serial: 8250_port: recognize UPIO_AU

Published Oct 23, 2026 CVSS 3.1 · 4.1 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-9019-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9020-1 Linux kernel vulnerabilities
History
Type Values Removed Values Added
Weaknesses CWE-20
Type Values Removed Values Added
Weaknesses CWE-617
References
Metrics threat_severity

None

cvssV3_1

{'score': 4.1, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
Weaknesses CWE-20
Type Values Removed Values Added
First Time appeared Linux linux
Vendors & Products Linux linux
Type Values Removed Values Added
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.
Title serial: 8250_port: recognize UPIO_AU
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Oct 26, 2026, 6:56 AM
Reserved
Sep 25, 2026, 10:25 AM
Status
Received
Published
Oct 23, 2026, 12:18 PM
Modified
Oct 26, 2026, 7:17 AM
Severity
Moderate
Public date
Oct 23, 2026, 12:00 AM