CVE-2023-4206

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.

Bugs

• <https://bugzilla.redhat.com/show_bug.cgi?id=2237757&gt;
• <https://bugzilla.suse.com/show_bug.cgi?id=1215110&gt;

Notes