CVE-2026-43442 (GCVE-0-2026-43442)
Vulnerability from cvelistv5 – Published: 2026-05-08 14:22 – Updated: 2026-05-08 14:22
VLAI?
Title
io_uring: fix physical SQE bounds check for SQE_MIXED 128-byte ops
Summary
In 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.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
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"value": "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."
}
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"providerMetadata": {
"dateUpdated": "2026-05-08T14:22:10.656Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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"url": "https://git.kernel.org/stable/c/1f794f9bed3e5cf7250a3b4daf112a72ed1513e9"
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{
"url": "https://git.kernel.org/stable/c/6f02c6b196036dbb6defb4647d8707d29b7fe95b"
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"title": "io_uring: fix physical SQE bounds check for SQE_MIXED 128-byte ops",
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"cveId": "CVE-2026-43442",
"datePublished": "2026-05-08T14:22:10.656Z",
"dateReserved": "2026-05-01T14:12:56.009Z",
"dateUpdated": "2026-05-08T14:22:10.656Z",
"state": "PUBLISHED"
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"epss": {
"cve": "CVE-2026-43442",
"date": "2026-05-10",
"epss": "0.00018",
"percentile": "0.05089"
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"nvd": "{\"cve\":{\"id\":\"CVE-2026-43442\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-05-08T15:16:56.663\",\"lastModified\":\"2026-05-08T15:16:56.663\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"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.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/1f794f9bed3e5cf7250a3b4daf112a72ed1513e9\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/6f02c6b196036dbb6defb4647d8707d29b7fe95b\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
}
}
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
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Nomenclature
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