A use-after-free vulnerability in the Linux kernel's net/sched: cls_fw component can be exploited to achieve local privilege escalation. When fw_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 76e42ae831991c828cffa8c37736ebfb831ad5ec.

** REJECT ** DO NOT USE THIS CVE RECORD. ConsultIDs: CVE-2023-4206, CVE-2023-4207, CVE-2023-4208. Reason: This record is a duplicate of CVE-2023-4206, CVE-2023-4207, CVE-2023-4208. Notes: All CVE users should reference CVE-2023-4206, CVE-2023-4207, CVE-2023-4208 instead of this record. All references and descriptions in this record have been removed to prevent accidental usage.