SB20261022236 - Race condition in Linux kernel s390 kvm

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-98649)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: 5.7 [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]

The vulnerability allows a local user to potentially cause a denial of service through a kernel crash.

The vulnerability exists due to a race condition in the Linux kernel s390 KVM function _destroy_pages_crste() when processing concurrently modified address translation entries. Separate reads of the same entry can yield inconsistent values for flag checks and address calculations. A local user can trigger this race to potentially cause invalid memory accesses and a kernel crash.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/4ca00a9154f998116fba9a32cce5bd938d228065
• https://git.kernel.org/stable/c/90bd832b2bc367991d424d847003ce345b454ffc