In the Linux kernel, the following vulnerability has been resolved: net/sched: act_api: release tail references on DELACTION failure A batched RTM_DELACTION request takes a temporary reference on each action before attempting any deletion. tcf_action_delete() clears each processed slot and drops its temporary reference before attempting the deletion. If deletion fails, tca_action_gd() calls tcf_action_put_many() to release the remaining references, but its tcf_act_for_each_action() iterator stops at the first NULL slot. When a batch stops at an action bound to a filter, this leaks a reference on each subsequent action. A later delete of an unbound action can then return success without removing it from the IDR. Walk the full array in tcf_action_put_many() and skip NULL slots to release the references held on the unprocessed actions.
https://git.kernel.org/stable/c/9eaba16f1b6ee19b249e6afd82c27f958d441458
https://git.kernel.org/stable/c/6e05e46fa821a5c1b281355f1f622ac76cb6080a
https://git.kernel.org/stable/c/57b477e46ef2df3483f3488cc713c61c4b384aab
https://git.kernel.org/stable/c/1be63e4579af408d596f0f3165faf1a880631d3b