CVE-2025-68760 iommu/amd: Fix potential out-of-bounds read in iommu_mmio_show
A local attacker with high privileges can trigger an out-of-bounds read in the AMD IOMMU driver, potentially disclosing sensitive kernel memory.
- 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-2025-68760?
CVE-2025-68760 is a vulnerability in Linux, published on 5 Jan 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 potential out-of-bounds read in iommu_mmio_show
In iommu_mmio_write(), it validates the user-provided offset with the check: `iommu->dbg_mmio_offset > iommu->mmio_phys_end - 4`. This assumes a 4-byte access. However, the corresponding show handler, iommu_mmio_show(), uses readq() to perform an 8-byte (64-bit) read.
If a user provides an offset equal to `mmio_phys_end - 4`, the check passes, and will lead to a 4-byte out-of-bounds read.
Fix this by adjusting the boundary check to use sizeof(u64), which corresponds to the size of the readq() operation.
Which versions are affected by CVE-2025-68760?
How do I fix CVE-2025-68760?
Apply the vendor's patch.
Is CVE-2025-68760 being exploited?
There is no known exploitation of CVE-2025-68760 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-68760, DEBIAN-CVE-2025-68760, GHSA-34rq-jg85-wh39, UBUNTU-CVE-2025-68760.