Linux Kernel net/sched/sch_hfsc.c hfsc_change_class use after free

Summaryinfo

A vulnerability was found in Linux Kernel and classified as critical. The impacted element is the function hfsc_change_class of the file net/sched/sch_hfsc.c. Executing a manipulation can lead to use after free. This vulnerability is handled as CVE-2023-4623. It is possible to launch the attack on the local host. There is not any exploit available. A patch should be applied to remediate this issue.

Detailsinfo

A vulnerability has been found in Linux Kernel (Operating System) (the affected version is unknown) and classified as critical. This vulnerability affects the function hfsc_change_class of the file net/sched/sch_hfsc.c. 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. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

A use-after-free vulnerability in the Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation. If a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free. We recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f.

The weakness was released 09/06/2023. The advisory is available at git.kernel.org. This vulnerability was named CVE-2023-4623 since 08/30/2023. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 08/26/2024).

Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.kernel.org.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

License

• open-source

Website

• Vendor: https://www.kernel.org/

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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