kernel: kernel: Denial of Service via race condition in s390 KVM storage key handling (CVE-2026-98650)

Overview

A flaw was found in the Linux kernel's KVM (Kernel-based Virtual Machine) subsystem for the s390 architecture. A race condition occurs when storage key management functions process large memory pages that are simultaneously split by another thread. A local user could exploit this timing issue during concurrent memory operations to crash the system, leading to a Denial of Service (DoS).

Vendor advisories

• Red Hat VEX · Moderate · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-10-21 · vex

kernel: kernel: Denial of Service via race condition in s390 KVM storage key handling — rated Moderate by Red Hat. Released 2026-10-18, updated 2026-10-21.

Affected:

• Red Hat Enterprise Linux 10

No fix planned:

• Red Hat Enterprise Linux 10

Remediation

Fix deferred

Workarounds / mitigations:

• Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.