Vulnerability Details CVE-2026-43442
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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 2.9%
CVSS Severity
CVSS v3 Score 7.1
References
Products affected by CVE-2026-43442
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cpe:2.3:o:linux:linux_kernel:6.19
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cpe:2.3:o:linux:linux_kernel:6.19.1
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cpe:2.3:o:linux:linux_kernel:6.19.3
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cpe:2.3:o:linux:linux_kernel:6.19.4
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cpe:2.3:o:linux:linux_kernel:6.19.6
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cpe:2.3:o:linux:linux_kernel:6.19.7
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cpe:2.3:o:linux:linux_kernel:6.19.8
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cpe:2.3:o:linux:linux_kernel:7.0