CVE-2026-99266
io_uring/zcrx: fix buffer offsets in areas above 4GB
In the Linux kernel, the following vulnerability has been resolved: io_uring/zcrx: fix buffer offsets in areas above 4GB io_zcrx_queue_cqe() computes the offset of the buffer in its area from net_iov_idx(), which is an unsigned int, so the shift is done in 32 bits and only the result is widened to the u64 that goes into the CQE. An area can be up to 1TB in size. For every niov beyond the first 4GB the CQE points the application at a buffer 4GB, or a multiple of that, below the one which has the data. It reads the wrong data, and then returns a buffer it doesn't own via the refill queue while the real one is never given back.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| Linux Linux |
≥ 11ed914bbf948c4a37248f2876973ac18014056d; < 9bfb315e2d0907fbcaf5d0453dd6d873c9aa8d5b (affected, git) ≥ 11ed914bbf948c4a37248f2876973ac18014056d; < 51f4ee29bf0564e6ae7d3540693a9bc1dd2c8fd7 (affected, git) Other versions: unaffected |
CNA: Linux |
| Linux Linux |
6.15 (affected) ≥ 0; < 6.15 (unaffected, semver) ≥ 6.18.60; ≤ 6.18.* (unaffected, semver) ≥ 7.2.14; ≤ 7.2.* (unaffected, semver) Other versions: affected |
CNA: Linux |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
No CVSS assessment reported. An unscored record is not a low-severity determination.
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
For agents and automation
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