Linux Kernel up to 6.6.25/6.8.4 kbuf io_buffer_list use after free

Summaryinfo

A vulnerability categorized as critical has been discovered in Linux Kernel up to 6.6.25/6.8.4. The impacted element is the function io_buffer_list of the component kbuf. The manipulation results in use after free. This vulnerability is known as CVE-2024-35880. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.6.25/6.8.4. Affected is the function io_buffer_list of the component kbuf. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: io_uring/kbuf: hold io_buffer_list reference over mmap If we look up the kbuf, ensure that it doesn't get unregistered until after we're done with it. Since we're inside mmap, we cannot safely use the io_uring lock. Rely on the fact that we can lookup the buffer list under RCU now and grab a reference to it, preventing it from being unregistered until we're done with it. The lookup returns the io_buffer_list directly with it referenced.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2024-35880 since 05/17/2024. The exploitability is told to be easy. 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 09/25/2025).

The vulnerability scanner Nessus provides a plugin with the ID 210815 (RHEL 9 : kernel (RHSA-2024:9315)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.26 or 6.8.5 eliminates this vulnerability. Applying the patch 65938e81df21/5fd8e2359498/561e4f9451d6 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.

The vulnerability is also documented in the vulnerability database at Tenable (210815). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.6.0
• 6.6.1
• 6.6.2
• 6.6.3
• 6.6.4
• 6.6.5
• 6.6.6
• 6.6.7
• 6.6.8
• 6.6.9
• 6.6.10
• 6.6.11
• 6.6.12
• 6.6.13
• 6.6.14
• 6.6.15
• 6.6.16
• 6.6.17
• 6.6.18
• 6.6.19
• 6.6.20
• 6.6.21
• 6.6.22
• 6.6.23
• 6.6.24
• 6.6.25
• 6.8.0
• 6.8.1
• 6.8.2
• 6.8.3
• 6.8.4

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Once again VulDB remains the best source for vulnerability data.

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