Linux Kernel Local Privilege io_uring use after free

Summaryinfo

A vulnerability described as very critical has been identified in Linux Kernel. This vulnerability affects the function io_uring of the component Local Privilege Handler. Such manipulation leads to use after free. This vulnerability is traded as CVE-2022-3910. The attack may be launched remotely. There is no exploit available. Applying a patch is advised to resolve this issue.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel (Operating System) (unknown version). Affected by this issue is the function io_uring of the component Local Privilege Handler. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Use After Free vulnerability in Linux Kernel allows Privilege Escalation. An improper Update of Reference Count in io_uring leads to Use-After-Free and Local Privilege Escalation. When io_msg_ring was invoked with a fixed file, it called io_fput_file() which improperly decreased its reference count (leading to Use-After-Free and Local Privilege Escalation). Fixed files are permanently registered to the ring, and should not be put separately. We recommend upgrading past commit https://github.com/torvalds/linux/commit/fc7222c3a9f56271fba02aabbfbae999042f1679 https://github.com/torvalds/linux/commit/fc7222c3a9f56271fba02aabbfbae999042f1679

The weakness was shared 11/22/2022 as fc7222c3a9f56271fba02aabbfbae999042f1679. The advisory is shared for download at github.com. This vulnerability is handled as CVE-2022-3910 since 11/09/2022. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 06/20/2025).

The vulnerability scanner Nessus provides a plugin with the ID 239841 (TencentOS Server 4: kernel (TSSA-2024:0960)), which helps to determine the existence of the flaw in a target environment.

Applying the patch fc7222c3a9f56271fba02aabbfbae999042f1679 is able to eliminate this problem. The bugfix is ready for download at github.com.

The vulnerability is also documented in the vulnerability database at Tenable (239841). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

License

• open-source

Website

• Vendor: https://www.kernel.org/

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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