Linux Kernel up to 2.6.20/6.5.3 push-switch flush_work use after free

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 2.6.20/6.5.3. This affects the function flush_work of the component push-switch. The manipulation leads to use after free. This vulnerability is listed as CVE-2023-52629. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 2.6.20/6.5.3. It has been rated as critical. This issue affects the function flush_work of the component push-switch. 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. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: sh: push-switch: Reorder cleanup operations to avoid use-after-free bug The original code puts flush_work() before timer_shutdown_sync() in switch_drv_remove(). Although we use flush_work() to stop the worker, it could be rescheduled in switch_timer(). As a result, a use-after-free bug can occur. The details are shown below: (cpu 0) | (cpu 1) switch_drv_remove() | flush_work() | ... | switch_timer // timer | schedule_work(&psw->work) timer_shutdown_sync() | ... | switch_work_handler // worker kfree(psw) // free | | psw->state = 0 // use This patch puts timer_shutdown_sync() before flush_work() to mitigate the bugs. As a result, the worker and timer will be stopped safely before the deallocate operations.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2023-52629 since 03/06/2024. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 03/29/2024).

Upgrading to version 2.6.20, 6.5.4 or 6.6 eliminates this vulnerability. Applying the patch 610dbd8ac271/246f80a0b17f 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.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 2.6.0
• 2.6.1
• 2.6.2
• 2.6.3
• 2.6.4
• 2.6.5
• 2.6.6
• 2.6.7
• 2.6.8
• 2.6.9
• 2.6.10
• 2.6.11
• 2.6.12
• 2.6.13
• 2.6.14
• 2.6.15
• 2.6.16
• 2.6.17
• 2.6.18
• 2.6.19
• 2.6.20
• 6.5.0
• 6.5.1
• 6.5.2
• 6.5.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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