Answer in brief
CVE-2021-47040 records a High severity (CVSS 7.8) vulnerability in io_uring: fix overflows checks in provide buffers. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=efe68c1ca8f49e8c06afd74b699411bfbb8ba1ff <cbbc13b115b8f18e0a714d89f87fbdc499acfe2d || >=efe68c1ca8f49e8c06afd74b699411bfbb8ba1ff <51bf90901952aaac564bbdb36b2b503050c53dd9 || >=efe68c1ca8f49e8c06afd74b699411bfbb8ba1ff <84b8c266c4bfe9ed5128e13253c388deb74b1b03 || >=efe68c1ca8f49e8c06afd74b699411bfbb8ba1ff <38134ada0ceea3e848fe993263c0ff6207fd46e7 | cbbc13b115b8f18e0a714d89f87fbdc499acfe2d, 51bf90901952aaac564bbdb36b2b503050c53dd9, 84b8c266c4bfe9ed5128e13253c388deb74b1b03, 38134ada0ceea3e848fe993263c0ff6207fd46e7 |
| Linux/Linuxgeneric | 5.8 | Not reported |
Published upstream
Feb 28, 2024
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 4, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 4, 2026
In the Linux kernel, the following vulnerability has been resolved: io_uring: fix overflows checks in provide buffers Colin reported before possible overflow and sign extension problems in io_provide_buffers_prep(). As Linus pointed out previous attempt did nothing useful, see d81269fecb8ce ("io_uring: fix provide_buffers sign extension"). Do that with help of check_<op>_overflow helpers. And fix struct io_provide_buf::len type, as it doesn't make much sense to keep it signed.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2021-47040 records a High severity (CVSS 7.8) vulnerability in io_uring: fix overflows checks in provide buffers. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=efe68c1ca8f49e8c06afd74b699411bfbb8ba1ff <cbbc13b115b8f18e0a714d89f87fbdc499acfe2d || >=efe68c1ca8f49e8c06afd74b699411bfbb8ba1ff <51bf90901952aaac564bbdb36b2b503050c53dd9 || >=efe68c1ca8f49e8c06afd74b699411bfbb8ba1ff <84b8c266c4bfe9ed5128e13253c388deb74b1b03 || >=efe68c1ca8f49e8c06afd74b699411bfbb8ba1ff <38134ada0ceea3e848fe993263c0ff6207fd46e7 | cbbc13b115b8f18e0a714d89f87fbdc499acfe2d, 51bf90901952aaac564bbdb36b2b503050c53dd9, 84b8c266c4bfe9ed5128e13253c388deb74b1b03, 38134ada0ceea3e848fe993263c0ff6207fd46e7 |
| Linux/Linuxgeneric | 5.8 | Not reported |
Published upstream
Feb 28, 2024
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 4, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 4, 2026
In the Linux kernel, the following vulnerability has been resolved: io_uring: fix overflows checks in provide buffers Colin reported before possible overflow and sign extension problems in io_provide_buffers_prep(). As Linus pointed out previous attempt did nothing useful, see d81269fecb8ce ("io_uring: fix provide_buffers sign extension"). Do that with help of check_<op>_overflow helpers. And fix struct io_provide_buf::len type, as it doesn't make much sense to keep it signed.
Quoted source text, attributed separately from HOL analysis.