Summaryinfo

A vulnerability has been found in Linux Kernel up to 5.10.36/5.11.20/5.12.3 and classified as critical. This vulnerability affects the function io_provide_buffers_prep of the component io_uring. The manipulation leads to buffer overflow. This vulnerability was named CVE-2021-47040. There is no exploit available. It is recommended to upgrade the affected component. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 5.10.36/5.11.20/5.12.3 (Operating System). This affects the function io_provide_buffers_prep of the component io_uring. The manipulation with an unknown input leads to a buffer overflow vulnerability. CWE is classifying the issue as CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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__overflow helpers. And fix struct io_provide_buf::len type, as it doesn't make much sense to keep it signed.

The weakness was released 02/28/2024. The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2021-47040 since 02/27/2024. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 01/09/2025).

Upgrading to version 5.10.37, 5.11.21, 5.12.4 or 5.13 eliminates this vulnerability. Applying the patch cbbc13b115b8/51bf90901952/84b8c266c4bf/38134ada0cee is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.0
• 5.10.1
• 5.10.2
• 5.10.3
• 5.10.4
• 5.10.5
• 5.10.6
• 5.10.7
• 5.10.8
• 5.10.9
• 5.10.10
• 5.10.11
• 5.10.12
• 5.10.13
• 5.10.14
• 5.10.15
• 5.10.16
• 5.10.17
• 5.10.18
• 5.10.19
• 5.10.20
• 5.10.21
• 5.10.22
• 5.10.23
• 5.10.24
• 5.10.25
• 5.10.26
• 5.10.27
• 5.10.28
• 5.10.29
• 5.10.30
• 5.10.31
• 5.10.32
• 5.10.33
• 5.10.34
• 5.10.35
• 5.10.36
• 5.11.0
• 5.11.1
• 5.11.2
• 5.11.3
• 5.11.4
• 5.11.5
• 5.11.6
• 5.11.7
• 5.11.8
• 5.11.9
• 5.11.10
• 5.11.11
• 5.11.12
• 5.11.13
• 5.11.14
• 5.11.15
• 5.11.16
• 5.11.17
• 5.11.18
• 5.11.19
• 5.11.20
• 5.12.0
• 5.12.1
• 5.12.2
• 5.12.3

License

• open-source

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