CVE-2026-68166
- Source
- https://cve.org/CVERecord?id=CVE-2026-68166
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-68166.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-68166
- Downstream
- Published
- 2026-08-10T11:59:34.576Z
- Modified
- 2026-08-12T04:19:21.548422248Z
- Summary
- userfaultfd: prevent registration of special VMAs
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
userfaultfd: prevent registration of special VMAs
Vova Tokarev says:
userfaultfd allows registration on shadow stack VMAs. With userfaultfd access, you can register on the shadow stack, discard a page ... and inject a page with chosen return addresses via UFFDIO_COPY.
Update vmacanuserfault() to reject VMSHADOWSTACK.
While on it, also reject VMSPECIAL so that if a driver would implement vmuffd_ops, it wouldn't be possible to register special VMAs with userfaultfd.
Since VMSPECIAL includes VMDONTEXPAND which is set but hugetlb, exclude hugetlb VMAs from the check for VM_SPECIAL.
- Database specific
{ "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68166.json", "cna_assigner": "Linux" }- References
-
- https://git.kernel.org/stable/c/0c26202b157f1efc3cd2f26f5c30f59b508a6a5d
- https://git.kernel.org/stable/c/165613191ad9d034bf17c00e3a142f9561597ec5
- https://git.kernel.org/stable/c/3c58f641e813c3c71039f8fd4d4e2a3aab713288
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68166.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-68166
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git