Bug 2395415 (CVE-2023-53205)

Summary: CVE-2023-53205 kernel: KVM: s390/diag: fix racy access of physical cpu number in diag 9c handler
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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Description OSIDB Bzimport 2025-09-15 15:12:37 UTC 
In the Linux kernel, the following vulnerability has been resolved:

KVM: s390/diag: fix racy access of physical cpu number in diag 9c handler

We do check for target CPU == -1, but this might change at the time we
are going to use it. Hold the physical target CPU in a local variable to
avoid out-of-bound accesses to the cpu arrays.
Comment 1 Jon Moroney 2025-09-15 17:16:37 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025091510-CVE-2023-53205-9a2b@gregkh/T