Bug 2516286 (CVE-2026-72290)

Summary: CVE-2026-72290 kernel: KVM: s390: pci: Fix GISC refcount leak on AIF enable failure
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: low    
Version: unspecifiedCC: rhel-process-autobot, 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 Kernel-based Virtual Machine (KVM) for s390 PCI. During the setup of guest interrupt forwarding, a reference count (refcount) to the Guest Interrupt Service Call (GISC) may not be properly released if subsequent setup steps fail. This resource leak can lead to resource exhaustion, potentially allowing a local attacker to cause a Denial of Service (DoS) to the virtualized environment.
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Description OSIDB Bzimport 2026-08-15 06:04:34 UTC 
In the Linux kernel, the following vulnerability has been resolved:

KVM: s390: pci: Fix GISC refcount leak on AIF enable failure

kvm_s390_gisc_register() registers the guest ISC before pinning
the guest interrupt forwarding pages and allocating the AISB bit.
If any of the later setup steps fails, the function unwinds the
pinned pages and other local state, but does not unregister the
GISC reference. Add the missing kvm_s390_gisc_unregister() to the
error unwind path.
Comment 1 gkamathe 2026-08-18 05:10:47 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081500-CVE-2026-72290-024c@gregkh/T