CVE Catalog

CVE-2026-43006

High
Published: Translated: NVD NIST

Summary

A vulnerability has been identified in the Linux kernel that allows the import of a zero-length buffer, leading to out-of-bounds memory reads. This issue occurs in the validate_fixed_range() function, where the lack of proper buffer length checking results in incorrect offset calculations.

Risk Assessment

This vulnerability may lead to unauthorized memory access, posing risks of data leakage or system instability. Organizations should be aware of the potential threats associated with the exploitation of this flaw.

Recommendation

It is recommended to update the Linux kernel to the latest version where this vulnerability has been fixed. Additionally, it is advisable to monitor systems for unauthorized operations related to io_uring.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: io_uring/rsrc: reject zero-length fixed buffer import validate_fixed_range() admits buf_addr at the exact end of the registered region when len is zero, because the check uses strict greater-than (buf_end > imu->ubuf + imu->len). io_import_fixed() then computes offset == imu->len, which causes the bvec skip logic to advance past the last bio_vec entry and read bv_offset from out-of-bounds slab memory. Return early from io_import_fixed() when len is zero. A zero-length import has no data to transfer and should not walk the bvec array at all. BUG: KASAN: slab-out-of-bounds in io_import_reg_buf+0x697/0x7f0 Read of size 4 at addr ffff888002bcc254 by task poc/103 Call Trace: io_import_reg_buf+0x697/0x7f0 io_write_fixed+0xd9/0x250 __io_issue_sqe+0xad/0x710 io_issue_sqe+0x7d/0x1100 io_submit_sqes+0x86a/0x23c0 __do_sys_io_uring_enter+0xa98/0x1590 Allocated by task 103: The buggy address is loc

Vulnerability data from NVD (NIST) · CISA KEV · EPSS