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.
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.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Tue, 03 Nov 2026 12:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | io_uring/zcrx: fix buffer offsets in areas above 4GB | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-11-03T11:48:17.035Z
Reserved: 2026-09-25T10:25:14.404Z
Link: CVE-2026-99266
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-11-03T12:17:33.747
Modified: 2026-11-03T12:17:33.747
Link: CVE-2026-99266
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.