Description
In the Linux kernel, the following vulnerability has been resolved:
dma-fence: Make dma_fence_dedup_array() robust against 0-count input
dma_fence_dedup_array() returns 1 when called with num_fences == 0:
the for-loop body never executes, j stays at 0, and the final
`return ++j` yields 1. This contradicts both the kernel-doc ("Return:
Number of unique fences remaining in the array") and the natural
expectation that 0 input gives 0 output.
The caller __dma_fence_unwrap_merge() bails out via the
`if (count == 0 || count == 1)` fast path and so is save.
But amdgpu_userq_wait_*() could reach the dedup call with a zero local
count and dereference an uninitialized fence slot in the array.
Make the contract match the documentation by returning 0 early. This
also skips an unnecessary sort() call on an empty array.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.16 | 6.18.40 |
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 | 7.1.5-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | linux | 7.0.0-38.38 | USN-8887-1 |
| Ubuntu 26.04 LTS | linux-aws +1 | 7.0.0-1014.14 | USN-8887-1 |
| Ubuntu 26.04 LTS | linux-azure | 7.0.0-1017.17 | USN-8888-1 |
| Ubuntu 26.04 LTS | linux-azure-fde | 7.0.0-1016.16 | USN-8888-1 |
| Ubuntu 26.04 LTS | linux-gke | 7.0.0-1008.9 | USN-8887-1 |
| Ubuntu 26.04 LTS | linux-ibm +1 | 7.0.0-1015.15 | USN-8889-1, USN-8887-1 |
| Ubuntu 26.04 LTS | linux-nvidia | 7.0.0-1025.26 | USN-9043-1 |
| Ubuntu 26.04 LTS | linux-nvidia-bos | 7.0.0-2022.23 | USN-9003-1 |
| Ubuntu 26.04 LTS | linux-oracle | 7.0.0-1013.13 | USN-8887-1 |
| Ubuntu 26.04 LTS | linux-raspi | 7.0.0-1023.23 | USN-9021-1 |
| Ubuntu 26.04 LTS | linux-riscv +1 | 7.0.0-38.38.1 | USN-8887-1 |
| Ubuntu 24.04 LTS | linux-aws-7.0 +1 | 7.0.0-1014.14~24.04.1 | USN-8887-3, USN-8887-2 |
| Ubuntu 24.04 LTS | linux-azure-7.0 | 7.0.0-1017.17~24.04.1 | USN-8888-2 |
| Ubuntu 24.04 LTS | linux-azure-fde-7.0 | 7.0.0-1016.16~24.04.1 | USN-8888-2 |
| Ubuntu 24.04 LTS | linux-hwe-7.0 | 7.0.0-38.38~24.04.4 | USN-8887-3 |
| Ubuntu 24.04 LTS | linux-nvidia-7.0 | 7.0.0-1024.25~24.04.1 | USN-9003-1 |
| Ubuntu 24.04 LTS | linux-oracle-7.0 | 7.0.0-1013.13~24.04.1 | USN-8887-3 |
| Ubuntu 24.04 LTS | linux-riscv +27 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-riscv-7.0 | 7.0.0-38.38.1~24.04.1 | — |
| 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 +1 | No fix yet | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.18.41-94.142 | 1:1.0-0.amzn2023 | ALAS2023-2026-2071 |
| Amazon Linux 2023 | perf6.18 +12 | 1:6.18.41-94.142.amzn2023 | ALAS2023-2026-2071 |
Advisories 11
- USN-9021-1 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-9043-1 linux-nvidia vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8887-1 linux, linux-aws, linux-gcp, linux-gke, linux-ibm, linux-oracle, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-9003-1 linux-nvidia-7.0, linux-nvidia-bos vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8887-3 linux-gcp-7.0, linux-hwe-7.0, linux-oracle-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8888-2 linux-azure-7.0, linux-azure-fde-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8888-1 linux-azure, linux-azure-fde vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8887-2 linux-aws-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8889-1 linux-oem-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- WID-SEC-2026-2852 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 11, 2026
- ALAS2023-2026-2071 Important: kernel6.18 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Sep 15, 2026