CVE-2026-43442 (GCVE-0-2026-43442)

Vulnerability from cvelistv5 – Published: 2026-05-08 14:22 – Updated: 2026-08-05 12:27
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
7.1 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 1cba30bf9fdd6c982708f3587f609a30c370d889 , < 1f794f9bed3e5cf7250a3b4daf112a72ed1513e9 (git)
Affected: 1cba30bf9fdd6c982708f3587f609a30c370d889 , < 6f02c6b196036dbb6defb4647d8707d29b7fe95b (git)
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Linux Linux Affected: 6.19
Unaffected: 0 , < 6.19 (semver)
Unaffected: 6.19.9 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
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