CVE-2023-4207

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.

• linux linux kernel (>= 3.18 < 4.14.326) • linux linux kernel (>= 4.15 < 4.19.295) • linux linux kernel (>= 4.20 < 5.4.253) • linux linux kernel (>= 5.5 < 5.10.190) • linux linux kernel (>= 5.11 < 5.15.126) • linux linux kernel (>= 5.16 < 6.1.45) • linux linux kernel (>= 6.2 < 6.4.10) • debian debian linux 12.0