io_uring/query: cap user size passed to copy_struct_to_user
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.
CVE-2026-81009
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-81009
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "c265ae75f900cea4e415230a77b5d152377627dd",
"lessThan": "417e02f7b6051765b91cf1289071882eebd172e0",
"versionType": "git"
},
{
"status": "affected",
"version": "c265ae75f900cea4e415230a77b5d152377627dd",
"lessThan": "2b8ad4981ecedb14c1fdd811ab977010b23933e6",
"versionType": "git"
},
{
"status": "affected",
"version": "c265ae75f900cea4e415230a77b5d152377627dd",
"lessThan": "ba77efee1b95b4ad7559b1cdbe7cd7fa36dca95b",
"versionType": "git"
}
],
"programFiles": [
"io_uring/query.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.18"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.18",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"io_uring/query.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-81009
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #34964 · Revision 1
- Added to Heist Feed
- Publisher date