Linux Kernel up to 6.6.25/6.8.4 ax25 ax25_dev_device_down use after free

Summaryinfo

A vulnerability classified as problematic has been found in Linux Kernel up to 6.6.25/6.8.4. The affected element is the function ax25_dev_device_down of the component ax25. This manipulation causes use after free. This vulnerability is tracked as CVE-2024-35887. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.6.25/6.8.4 and classified as problematic. Affected by this vulnerability is the function ax25_dev_device_down of the component ax25. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: ax25: fix use-after-free bugs caused by ax25_ds_del_timer When the ax25 device is detaching, the ax25_dev_device_down() calls ax25_ds_del_timer() to cleanup the slave_timer. When the timer handler is running, the ax25_ds_del_timer() that calls del_timer() in it will return directly. As a result, the use-after-free bugs could happen, one of the scenarios is shown below: (Thread 1) | (Thread 2) | ax25_ds_timeout() ax25_dev_device_down() | ax25_ds_del_timer() | del_timer() | ax25_dev_put() //FREE | | ax25_dev-> //USE In order to mitigate bugs, when the device is detaching, use timer_shutdown_sync() to stop the timer.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2024-35887 since 05/17/2024. 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 02/25/2025).

The vulnerability scanner Nessus provides a plugin with the ID 216710 (Ubuntu 22.04 LTS : Linux kernel vulnerabilities (USN-7288-1)), 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 74204bf9050f/c6a368f9c7af/fd819ad3ecf6 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 (216710). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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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Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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