CVE-2026-43253
iommu/amd: move wait_on_sem() out of spinlock
Reported by linux · Published May 6, 2026
In the Linux kernel, the following vulnerability has been resolved: iommu/amd: move wait_on_sem() out of spinlock With iommu.strict=1, the existing completion wait path can cause soft lockups under stressed environment, as wait_on_sem() busy-waits under the spinlock with interrupts disabled. Move the completion wait in iommu_completion_wait() out of the spinlock. wait_on_sem() only polls the hardware-updated cmd_sem and does not require iommu->lock, so holding the lock during the busy wait unnecessarily increases contention and extends the time with interrupts disabled.
Fixed versions
Upgrade to a fixed version or later. Language registries are listed first, then Linux distributions, then vendor products.
| Package | Ecosystem | Fixed in |
|---|---|---|
| kernel6.18-libbpf | Amazon Linux | 1:6.18.16-18.222.amzn2023 |
| kernel6.18-tools | Amazon Linux | 1:6.18.16-18.222.amzn2023 |
| kernel6.12-modules-extra-common | Amazon Linux | 1:6.12.77-99.140.amzn2023 |
| kernel6.12-modules-extra | Amazon Linux | 1:6.12.77-99.140.amzn2023 |
| kernel6.12-tools-devel | Amazon Linux | 1:6.12.77-99.140.amzn2023 |
| bpftool6.18 | Amazon Linux | 1:6.18.16-18.222.amzn2023 |
| kernel6.18 | Amazon Linux | 1:6.18.16-18.222.amzn2023 |
| kernel6.18-devel | Amazon Linux | 1:6.18.16-18.222.amzn2023 |
| perf6.18 | Amazon Linux | 1:6.18.16-18.222.amzn2023 |
| bpftool6.12 | Amazon Linux | 1:6.12.77-99.140.amzn2023 |
| kernel-livepatch-6.18.16-18.222 | Amazon Linux | 1:1.0-0.amzn2023 |
| python3-perf6.18 | Amazon Linux | 1:6.18.16-18.222.amzn2023 |
1 more packages have a fixed version. See every fix in Lookup.
Risk scores
Affected products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | 4bf5beef578e46393f11eb69dda7d17a065e05ff, 4bf5beef578e46393f11eb69dda7d17a065e05ff, 4bf5beef578e46393f11eb69dda7d17a065e05ff |
| Linux | Linux | 4.9, 0, 6.1.191 |
| amazon:2023 | kernel6.18-libbpf | 0 |
| amazon:2023 | kernel6.18-tools | 0 |
| amazon:2023 | kernel6.12-modules-extra-common | 0 |
| amazon:2023 | kernel6.12-modules-extra | 0 |
| amazon:2023 | kernel6.12-tools-devel | 0 |
| amazon:2023 | bpftool6.18 | 0 |
| amazon:2023 | kernel6.18 | 0 |
| amazon:2023 | kernel6.18-devel | 0 |
| amazon:2023 | perf6.18 | 0 |
| amazon:2023 | bpftool6.12 | 0 |
| amazon:2023 | kernel-livepatch-6.18.16-18.222 | 0 |
| amazon:2023 | python3-perf6.18 | 0 |
| amazon:2023 | kernel6.12 | 0 |
| Linux | Linux | 7.0, 4bf5beef578e46393f11eb69dda7d17a065e05ff, 4bf5beef578e46393f11eb69dda7d17a065e05ff |
| amazon:2023 | kernel6.12-libbpf-static | 0 |
| amazon:2023 | kernel6.18-modules-extra-common | 0 |
| amazon:2023 | kernel6.18-headers | 0 |
| amazon:2023 | kernel6.12-devel | 0 |
…and 12 more
Timeline
- May 6, 2026 CVE Published
- May 6, 2026 Security Advisory (96 in total, the first dated here)
- May 18, 2026 EPSS Score (30 in total, the first dated here)
- Aug 4, 2026 Coalition ESS Score
- Aug 11, 2026 Distribution Patch (91 in total, the first dated here)
Query this with the API
The same record, from the CLI:
vulnetix vdb vuln CVE-2026-43253
vulnetix vdb fixes CVE-2026-43253Or with curl, using the org id and key from your account page:
curl -s -H "Authorization: ApiKey ${VULNETIX_ORG_ID}:${VULNETIX_API_KEY}" \
"https://api.vdb.vulnetix.com/v2/vuln/CVE-2026-43253/fixes/registry"The Community plan is free and allows 50 queries a day. Get a free API key · API quickstart