A use-after-free vulnerability in the Linux kernel's net/sched: cls_fw component can be exploited to achieve local privilege escalation.
If tcfchangeindev() fails, fwsetparms() will immediately return an error after incrementing or decrementing the reference counter in tcfbindfilter(). If an attacker can control the reference counter and set it to zero, they can cause the reference to be freed, leading to a use-after-free vulnerability.
We recommend upgrading past commit 0323bce598eea038714f941ce2b22541c46d488f.