CVE-2026-89453 iommu/amd: Put PCI device after handling PPR faults
A reference count leak in the AMD IOMMU driver allows attackers to exhaust kernel memory, causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-89453?
CVE-2026-89453 is a denial of service vulnerability in Linux, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-89453?
How do I fix CVE-2026-89453?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-89453 being exploited?
There is no known exploitation of CVE-2026-89453 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-89453, DEBIAN-CVE-2026-89453, GHSA-j994-7rwj-c4pp, UBUNTU-CVE-2026-89453.