In the Linux kernel, the following vulnerability has been resolved: net/sched: act_api: avoid dereferencing ERR_PTR in tcf_idrinfo_destroy syzbot reported a crash in tc_act_in_hw() during netns teardown where tcf_idrinfo_destroy() passed an ERR_PTR(-EBUSY) value as a tc_action pointer, leading to an invalid dereference. Guard against ERR_PTR entries when iterating the action IDR so teardown does not call tc_act_in_hw() on an error pointer.
https://git.kernel.org/stable/c/adb25a46dc0a43173f5ea5f5f58fc8ba28970c7c
https://git.kernel.org/stable/c/67550a1130b647bb0d093c9c0a810c69aa6a30a8