SB2026070274 - Improper locking in Linux kernel lib

Description

This security bulletin contains information about 1 vulnerability.

1) Improper locking (CVE-ID: CVE-2026-53326)

CWE-ID: CWE-667 - Improper Locking

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

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

The vulnerability exists due to improper lock handling in debugobjects pool refill logic in lib/debugobjects.c when handling hard interrupts during early boot on PREEMPT_RT kernels. A local user can trigger an interrupt in a context that holds a lock required by the allocation path to cause a denial of service.

Exploitation requires a debug PREEMPT_RT kernel on an ARM64 system during the early boot window before scheduling is enabled.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/0d046ae106255cba5eb83b23f78ee93f3620247d
• https://git.kernel.org/stable/c/44b8b03a9fb5c575548fc72c674653d6baba142a
• https://git.kernel.org/stable/c/7bc71bdb1c1526c7f02a6adab324394ff1327b0a