CVE-2026-92505 iommu/amd: Fix undefined behavior in devid_write debugfs function
A local attacker with debugfs access can trigger undefined behavior in the AMD IOMMU driver, potentially causing a system crash.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-92505?
CVE-2026-92505 is a vulnerability in Linux, published on 17 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: Fix undefined behavior in devid_write debugfs function
When for_each_pci_segment() loop completes without finding a matching segment, the pci_seg pointer is not NULL but points to an invalid memory location (the list head). Accessing pci_seg->id after the loop causes undefined behavior.
Fix this by handling the successful case inside the loop and returning -EINVAL after the loop if no matching segment is found.
Which versions are affected by CVE-2026-92505?
How do I fix CVE-2026-92505?
Apply the vendor's patch.
Is CVE-2026-92505 being exploited?
There is no known exploitation of CVE-2026-92505 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-92505, DEBIAN-CVE-2026-92505, GHSA-2mxc-qwhf-8gfr, UBUNTU-CVE-2026-92505.