CVE-2026-43006
Description
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 located 12 bytes to the right of allocated 584-byte region [ffff888002bcc000, ffff888002bcc248)
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | fixed | 0 |
| debian | bullseye | fixed | 0 |
| debian | forky | fixed | 6.19.12-1 |
| debian | sid | fixed | 6.19.12-1 |
| debian | trixie | fixed | 0 |
| linux-kernel | affected | 6.18.22 | |
| linux-kernel | 7.0 | affected | |
References
- https://git.kernel.org/stable/c/040a1e7e0e2f01851fec1dd2d96906f8636a9f75
- https://git.kernel.org/stable/c/111a12b422a8cfa93deabaef26fec48237163214
- https://git.kernel.org/stable/c/40170fc1a79c1b2e68f09ae6aac687b7305ae6f4
- https://www.suse.com/security/cve/CVE-2026-43006.html
- https://security-tracker.debian.org/tracker/CVE-2026-43006
CWEs
CWE-125
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.