CVE-2026-89453

Received Received - Intake

PCI Device Reference Leak in Linux Kernel IOMMU

Publication date: 2026-09-11

Last updated on: 2026-09-11

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: iommu/amd: Put PCI device after handling PPR faults iommu_call_iopf_notifier() looks up the requester with pci_get_domain_bus_and_slot(), which returns a PCI device with its reference count incremented. Neither the successful iommu_report_device_fault() path nor the abort path drops that reference, so every handled PPR request leaks a PCI device reference. This is the same ownership rule that was fixed for the old iommu_v2 ppr_notifier() path by commit 6cf0981c2233 ("iommu/amd: Fix pci device refcount leak in ppr_notifier()"), but iommu_call_iopf_notifier() was added later as a separate PPR/IOPF notifier path. Drop the PCI device reference after handling the PPR entry.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-11

Last Modified

2026-09-11

Generated

2026-10-02

AI Q&A

2026-09-12

EPSS Evaluated

2026-10-01

NVD

CVE-2026-89453

EUVD

EUVD-2026-76359

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves a reference count leak in the IOMMU AMD driver. When handling PPR faults, the function iommu_call_iopf_notifier() increments the reference count of a PCI device but fails to decrement it afterward. This causes a memory leak where the PCI device reference is never released.

Detection Guidance

This vulnerability is specific to the Linux kernel's IOMMU AMD driver and does not have direct network detection methods. Detection involves checking kernel logs for PPR fault handling errors or PCI device reference leaks. Use commands like dmesg | grep -i iommu or journalctl -k | grep -i amd to review kernel logs for related errors.

Impact Analysis

The vulnerability can lead to resource exhaustion over time. Since PCI device references are not properly released, the system may run out of available references, potentially causing device or system instability, crashes, or degraded performance.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards as it involves a reference leak in the Linux kernel's IOMMU subsystem. Compliance impacts would depend on system-specific configurations and usage rather than this technical flaw.

Mitigation Strategies

Update your Linux kernel to the latest stable version that includes the fix for this vulnerability. Monitor kernel updates from your distribution vendor and apply patches promptly. No additional configuration changes are required beyond the kernel update.

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