SB20260727374 - Improper Check or Handling of Exceptional Conditions in Linux kernel rcu

Description

This security bulletin contains information about 1 vulnerability.

1) Improper Check or Handling of Exceptional Conditions (CVE-ID: CVE-2026-64211)

CWE-ID: CWE-703 - Improper Check or Handling of Exceptional Conditions

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 cpu online state in Tree SRCU callback scheduling in kernel/rcu/srcutree.c when invoking SRCU operations on a CPU that is not yet fully online. A local user can trigger SRCU callback processing from such a CPU to cause a denial of service.

The issue can result in hangs on s390 systems.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/593889c401426004bd0ea0f6d4fcece728b03420
• https://git.kernel.org/stable/c/a4153538fcd2361c4e0039eb103265492d26044e