All vulnerabilities
CVE-2026-98883

Linux: serial: 8250_port: recognize UPIO_AU

Linux LinuxOperating systems
Open in ThreatlineRecord JSON
CVSS
NoneNot scored
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)No scoreNo FIRST EPSS score in this snapshot yet
Fixed in9f67997353caa29c6a080789a1fb6e01fb50c118Also 49fa670efdfdd27e29145cbd2beef065c08717ef, 6.18.53CVE List
Published23 Oct 2026Updated 23 Oct 2026CVE List

What fixes it

  • 9f67997353caa29c6a080789a1fb6e01fb50c118LinuxCVE List
  • 49fa670efdfdd27e29145cbd2beef065c08717efLinuxCVE List
  • 6.18.53LinuxCVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

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.

Text from CVE List

Affected versions 5

  • Linuxaffected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 9f67997353caa29c6a080789a1fb6e01fb50c118CVE List
  • Linuxaffected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 49fa670efdfdd27e29145cbd2beef065c08717efCVE List
  • Linuxaffected: all versions before 6.18.53CVE List
  • Linuxunaffected: 6.18.53 through 6.18.*CVE List
  • Linuxunaffected: 7.2CVE List

References 2