GHSA-CMW3-52P3-WRX5
Vulnerability from github – Published: 2026-05-08 15:31 – Updated: 2026-05-11 09:30In the Linux kernel, the following vulnerability has been resolved:
io_uring: fix physical SQE bounds check for SQE_MIXED 128-byte ops
When IORING_SETUP_SQE_MIXED is used without IORING_SETUP_NO_SQARRAY, the boundary check for 128-byte SQE operations in io_init_req() validated the logical SQ head position rather than the physical SQE index.
The existing check:
!(ctx->cached_sq_head & (ctx->sq_entries - 1))
ensures the logical position isn't at the end of the ring, which is correct for NO_SQARRAY rings where physical == logical. However, when sq_array is present, an unprivileged user can remap any logical position to an arbitrary physical index via sq_array. Setting sq_array[N] = sq_entries - 1 places a 128-byte operation at the last physical SQE slot, causing the 128-byte memcpy in io_uring_cmd_sqe_copy() to read 64 bytes past the end of the SQE array.
Replace the cached_sq_head alignment check with a direct validation of the physical SQE index, which correctly handles both sq_array and NO_SQARRAY cases.
{
"affected": [],
"aliases": [
"CVE-2026-43442"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-08T15:16:56Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring: fix physical SQE bounds check for SQE_MIXED 128-byte ops\n\nWhen IORING_SETUP_SQE_MIXED is used without IORING_SETUP_NO_SQARRAY,\nthe boundary check for 128-byte SQE operations in io_init_req()\nvalidated the logical SQ head position rather than the physical SQE\nindex.\n\nThe existing check:\n\n !(ctx-\u003ecached_sq_head \u0026 (ctx-\u003esq_entries - 1))\n\nensures the logical position isn\u0027t at the end of the ring, which is\ncorrect for NO_SQARRAY rings where physical == logical. However, when\nsq_array is present, an unprivileged user can remap any logical\nposition to an arbitrary physical index via sq_array. Setting\nsq_array[N] = sq_entries - 1 places a 128-byte operation at the last\nphysical SQE slot, causing the 128-byte memcpy in\nio_uring_cmd_sqe_copy() to read 64 bytes past the end of the SQE\narray.\n\nReplace the cached_sq_head alignment check with a direct validation\nof the physical SQE index, which correctly handles both sq_array and\nNO_SQARRAY cases.",
"id": "GHSA-cmw3-52p3-wrx5",
"modified": "2026-05-11T09:30:31Z",
"published": "2026-05-08T15:31:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43442"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1f794f9bed3e5cf7250a3b4daf112a72ed1513e9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6f02c6b196036dbb6defb4647d8707d29b7fe95b"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
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Nomenclature
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