CVE-2026-81009

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.

CVSS

No CVSS.

References

Link	Resource
https://git.kernel.org/stable/c/2b8ad4981ecedb14c1fdd811ab977010b23933e6
https://git.kernel.org/stable/c/417e02f7b6051765b91cf1289071882eebd172e0
https://git.kernel.org/stable/c/ba77efee1b95b4ad7559b1cdbe7cd7fa36dca95b

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-11 20:19

Updated : 2026-09-11 20:19

NVD link : CVE-2026-81009

Mitre link : CVE-2026-81009

CVE.ORG link : CVE-2026-81009

JSON object : View

Products Affected

No product.

CWE

No CWE.

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