Bug 2554937 (CVE-2026-98649)

Summary: CVE-2026-98649 kernel: KVM: s390: Fix race in _destroy_pages_crste()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's KVM (Kernel-based Virtual Machine) subsystem on s390 architectures. A local attacker can exploit this vulnerability to cause a Denial of Service (DoS) or memory corruption by triggering a race condition during guest memory page destruction. This issue occurs because memory management table entries are read multiple times concurrently without proper synchronization, allowing values to change between validation and use.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-10-18 15:33:53 UTC 
In the Linux kernel, the following vulnerability has been resolved:

KVM: s390: Fix race in _destroy_pages_crste()

Use READ_ONCE() in _destroy_pages_crste() to read the crste, avoid
dereferencing the pointer multiple times.