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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.17 | 6.17.13 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 6.17.13-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 25.10 | linux | 6.17.0-19.19 | USN-8094-1 |
| Ubuntu 25.10 | linux-aws +2 | 6.17.0-1009.9 | USN-8094-1 |
| Ubuntu 25.10 | linux-azure +1 | 6.17.0-1010.10 | USN-8094-5, USN-8094-4 |
| Ubuntu 25.10 | linux-azure-fde | No fix yet | — |
| Ubuntu 25.10 | linux-realtime | 6.17.0-1008.9 | USN-8094-2 |
| Ubuntu 25.10 | linux-riscv | 6.17.0-19.19.1 | — |
| Ubuntu 24.04 LTS | linux-aws-6.17 | 6.17.0-1009.9~24.04.2 | USN-8094-1 |
| Ubuntu 24.04 LTS | linux-azure-6.17 | 6.17.0-1010.10~24.04.1 | USN-8094-4 |
| Ubuntu 24.04 LTS | linux-gcp-6.17 | 6.17.0-1009.9~24.04.3 | USN-8094-2 |
| Ubuntu 24.04 LTS | linux-hwe-6.17 | 6.17.0-19.19~24.04.2 | USN-8094-1 |
| Ubuntu 24.04 LTS | linux-nvidia-6.17 | 6.17.0-1018.18 | — |
| Ubuntu 24.04 LTS | linux-oem-6.17 | 6.17.0-1017.17 | USN-8152-1 |
| Ubuntu 24.04 LTS | linux-oracle-6.17 | 6.17.0-1009.9~24.04.1 | USN-8094-1 |
| Ubuntu 24.04 LTS | linux-riscv +10 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-riscv-6.17 | 6.17.0-19.19.1~24.04.1 | — |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.17 | 6.17.0-1008.9~24.04.1 | USN-8094-3 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | kernel-source | 6.18.5-1.1 | openSUSE-SU-2026:10039-1 |
| openSUSE Tumbleweed | kernel-source-longterm | 6.18.16-1.1 | openSUSE-SU-2026:10301-1 |
Advisories 9
- WID-SEC-2026-0009 Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8094-1 linux, linux-aws, linux-aws-6.17, linux-gcp, linux-hwe-6.17, linux-oracle, linux-oracle-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8094-2 linux-gcp-6.17, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8152-1 linux-oem-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8094-3 linux-realtime-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8094-4 linux-azure, linux-azure-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8094-5 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- openSUSE-SU-2026:10039-1 kernel-devel-6.18.5-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2026:10301-1 kernel-devel-longterm-6.18.16-1.1 on GA media SUSE / openSUSE Security Updates · Mar 8, 2026