CVE-2026-81009
- Source
- https://cve.org/CVERecord?id=CVE-2026-81009
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-81009.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-81009
- Downstream
- Published
- 2026-09-11T19:43:00Z
- Modified
- 2026-09-13T03:47:10Z
- Summary
- io_uring/query: cap user size passed to copy_struct_to_user
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
io_uring/query: cap user size passed to copy_struct_to_user
io_handle_query_entry() clamps hdr.size for the inbound copy_from_user() but keeps the original user value as usize. copy_struct_to_user() uses that usize and, when it is larger than the kernel result, clear_user()s the trailing bytes.
As hdr.size is a __u32, a query can request nearly 4 GiB of zeroing, including on the error path where res_size stays 0. The interface is reachable without a ring via IORING_REGISTER_QUERY.
Reject sizes larger than PAGE_SIZE, as recommended for copy_struct_* interfaces.
- Database specific
{ "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81009.json" }- References
-
- https://git.kernel.org/stable/c/2b8ad4981ecedb14c1fdd811ab977010b23933e6
- https://git.kernel.org/stable/c/417e02f7b6051765b91cf1289071882eebd172e0
- https://git.kernel.org/stable/c/ba77efee1b95b4ad7559b1cdbe7cd7fa36dca95b
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81009.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-81009
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git