CVE-2023-4206 Information

Description

A use-after-free vulnerability in the Linux kernel’s net/sched: cls_route component can be exploited to achieve local privilege escalation.

When route4_change() is called on an existing filter the whole tcf_result struct is always copied into the new instance of the filter. This causes a problem when updating a filter bound to a class as tcf_unbind_filter() is always called on the old instance in the success path decreasing filter_cnt of the still referenced class and allowing it to be deleted leading to a use-after-free.

We recommend upgrading past commit b80b829e9e2c1b3f7aae34855e04d8f6ecaf13c8.

Reference

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b80b829e9e2c1b3f7aae34855e04d8f6ecaf13c8 https://kernel.dance/b80b829e9e2c1b3f7aae34855e04d8f6ecaf13c8