SB20260824167 - Always-Incorrect Control Flow Implementation in Linux kernel serial 8250 driver

Description

This security bulletin contains information about 1 vulnerability.

1) Always-Incorrect Control Flow Implementation (CVE-ID: CVE-2026-74653)

CWE-ID: CWE-670 - Always-Incorrect Control Flow Implementation

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper handling of a stuck RX timeout condition in 8250_of for the LPC32xx UART when handling serial port interrupts. A local user can repeatedly open the front-panel serial port to cause a denial of service.

The issue can trigger a persistent interrupt storm that livelocks the CPU and trips the soft-lockup detector on affected single-core systems.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/1423415471274abda87024967d7fe2206ceee0ea
• https://git.kernel.org/stable/c/3ce24bc4d115336218e59b7e286fd3a79f4fc4c6
• https://git.kernel.org/stable/c/7795e8abedc86438cae0454602cbf9038b94bf38