Bug 2516397 (CVE-2026-72283)

Summary: CVE-2026-72283 kernel: KVM: x86: Nullify irqfd->producer if updating IRTE for bypass fails
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: 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 KVM (Kernel-based Virtual Machine) subsystem. This vulnerability occurs when the system fails to update an Interrupt Remapping Table Entry (IRTE) for a bypass operation, which can leave a pointer to a memory location that has already been freed (a 'dangling pointer'). If this dangling pointer is later accessed, it can lead to a 'use-after-free' condition, where the system attempts to use deallocated memory. This could result in system instability, crashes, or potentially allow an attacker to execute arbitrary code.
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Description OSIDB Bzimport 2026-08-15 06:10:20 UTC 
In the Linux kernel, the following vulnerability has been resolved:

KVM: x86: Nullify irqfd->producer if updating IRTE for bypass fails

Nullify irqfd->producer if updating the IRTE for bypass fails, as leaving a
dangling pointer will result in a use-after-free if the irqfd is reachable
through KVM's routing, but the producer is freed separately.  E.g. for VFIO
PCI, the producer is embedded in struct "vfio_pci_irq_ctx" and freed when
the vector is disabled, which can happen independent of routing updates.

[sean: drop PPC change, massage changelog]
Comment 1 Keith Grant 2026-08-18 18:50:28 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081559-CVE-2026-72283-8563@gregkh/T