CVE-2026-43130 iommu/vt-d: Flush dev-IOTLB only when PCIe device is accessible in scalable mode
A flaw in the Linux kernel's IOMMU driver causes a system hard-lockup when releasing resources for disconnected PCIe devices, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-43130?
CVE-2026-43130 is a medium-severity denial of service vulnerability in Linux kernel, published on 6 May 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/vt-d: Flush dev-IOTLB only when PCIe device is accessible in scalable mode
Commit 4fc82cd907ac ("iommu/vt-d: Don't issue ATS Invalidation request when device is disconnected") relies on pci_dev_is_disconnected() to skip ATS invalidation for safely-removed devices, but it does not cover link-down caused by faults, which can still hard-lock the system.
For example, if a VM fails to connect to the PCIe device, "virsh destroy" is executed to release resources and isolate the fault, but a hard-lockup occurs while releasing the group fd.
Call Trace: qi_submit_sync qi_flush_dev_iotlb intel_pasid_tear_down_entry device_block_translation blocking_domain_attach_dev __iommu_attach_device __iommu_device_set_domain __iommu_group_set_domain_internal iommu_detach_group vfio_iommu_type1_detach_group vfio_group_detach_container vfio_group_fops_release __fput
Although pci_device_is_present() is slower than pci_dev_is_disconnected(), it still takes only ~70 µs on a ConnectX-5 (8 GT/s, x2) and becomes even faster as PCIe speed and width increase.
Besides, devtlb_invalidation_with_pasid() is called only in the paths below, which are far less frequent than memory map/unmap.
1. mm-struct release 2. {attach,release}_dev 3. set/remove PASID 4. dirty-tracking setup
The gain in system stability far outweighs the negligible cost of using pci_device_is_present() instead of pci_dev_is_disconnected() to decide when to skip ATS invalidation, especially under GDR high-load conditions.
Which versions are affected by CVE-2026-43130?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43130?
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-2026-43130 being exploited?
There is no known exploitation of CVE-2026-43130 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-43130, DEBIAN-CVE-2026-43130, GHSA-m67f-9cj9-483j, ROOT-OS-DEBIAN-11-CVE-2026-43130, ROOT-OS-UBUNTU-2204-CVE-2026-43130, ROOT-OS-UBUNTU-2404-CVE-2026-43130 and 1 more.