CVE-2026-80633: Linux kernel · iommufd: Take dma_resv lock before dma_buf_unpin() in release path
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.8 High.
Data as of 12 Nov 2026, 20:33 UTC
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 28 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 12 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-aws-6.17pkg:deb/ubuntu/linux-aws-6.17?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.14pkg:deb/ubuntu/linux-azure-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.17pkg:deb/ubuntu/linux-azure-6.17?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-fde-6.14pkg:deb/ubuntu/linux-azure-fde-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available that ensures the dma_resv lock is taken before calling dma_buf_unpin() in iopt_release_pages(). Users should apply the official kernel updates that include this fix to affected versions. Since this is a kernel-level issue, updating to patched kernel versions is the recommended remediation.
Description
CVE-2026-80633 is a high-severity vulnerability in the Linux kernel's iommufd component. It involves improper locking around the dma_buf_unpin() function in the release path, which can trigger warnings and potentially lead to race conditions or inconsistent states. The issue arises because iopt_release_pages() calls dma_buf_unpin() without holding the required dma_resv lock, violating the expected locking convention. The fix involves taking the dma_resv lock around dma_buf_unpin() in iopt_release_pages() to match the locking behavior of iopt_map_dmabuf().
References
- ubuntu.com/security/CVE-2026-80633 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-80633 (opens in a new tab)
- git.kernel.org/linus/e745cd2c749e557c14a15ac931761c3f58c24489 (opens in a new tab)
- git.kernel.org/stable/c/cc69d0332421fd2943b66dbe5e597bf4fd5af126 (opens in a new tab)
- git.kernel.org/stable/c/e745cd2c749e557c14a15ac931761c3f58c24489 (opens in a new tab)