SB2026032566 - Improper Synchronization in Linux kernel trace

Description

This security bulletin contains information about 1 vulnerability.

1) Improper Synchronization (CVE-ID: CVE-2026-23374)

CWE-ID: CWE-662 - Improper Synchronization

CVSSv4: 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/E:U/U:Clear

The vulnerability allows a local user to cause a denial of service or potentially execute arbitrary code.

The vulnerability exists due to improper synchronization in the blktrace component when handling block I/O tracing operations. A local user can trigger a use of __this_cpu_read/write in a preemptible context to cause a kernel BUG and system crash.

The issue arises in process context where preemption is enabled, violating the requirement for preemption to be disabled when accessing per-CPU variables via __this_cpu_read/write. This can lead to undefined behavior including memory corruption.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/59efa088752b1c380a0475974679850cc8aef907
• https://git.kernel.org/stable/c/da46b5dfef48658d03347cda21532bcdbb521e67