Vulnerability in Linux kernel (CVE-2026-80633)
Summary
Vulnerability in Linux kernel (CVE-2026-80633). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
iommufd: Take dma_resv lock before dma_buf_unpin() in release path
dma_buf_unpin() requires the caller to hold the exporter's dma_resv
lock:
void dma_buf_unpin(struct dma_buf_attachment *attach)
{
...
dma_resv_assert_held(dmabuf->resv);
...
}
iopt_release_pages() calls dma_buf_unpin() without taking that lock,
so every iommufd_ioas_destroy()/iommufd_ioas_unmap() that releases
the last reference on a DMABUF-backed iopt_pages triggers a WARN.
This was hit while running tools/testing/selftests/iommu/iommufd:
WARNING: drivers/dma-buf/dma-buf.c:1137 at dma_buf_unpin+0x62/0x70
RIP: 0010:dma_buf_unpin+0x62/0x70
Call Trace:
dma_buf_unpin+0x62/0x70
iopt_release_pages+0xe4/0x190
iopt_unmap_iova_range+0x1c7/0x290
iopt_unmap_all+0x1a/0x30
iommufd_ioas_destroy+0x1d/0x50
iommufd_fops_release+0x93/0x150
__fput+0xfc/0x2c0
__x64_sys_close+0x3d/0x80
do_syscall_64+0x65/0x180
Take the dma_resv lock around dma_buf_unpin() in iopt_release_pages(),
matching the iopt_map_dmabuf() convention. dma_buf_detach() acquires the
reservation lock internally, so it must remain outside the locked region.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-80633 has been found in Linux kernel.
Successful exploitation can lead to full system takeover. CVSS score: 8.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-80633" on the vendor's site.
CVE-2026-80633 (Linux kernel) — CVSS v3 8.8
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: High (CVSS 8.8/10). Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-80633
- Debian DEBIAN-CVE-2026-80633 linux Fixed in: 7.1.5-1
- Ubuntu UBUNTU-CVE-2026-80633 linux-hwe-edge
References
- advisory nvd.nist.gov
- advisory github.com
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web github.com