Commit b98a5c68 authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Daniel Borkmann
Browse files

bpf: Do not walk twice the map on free 



If someone stores both a timer and a workqueue in a map, on free
we would walk it twice.

Add a check in array_map_free_timers_wq and free the timers and
workqueues if they are present.

Fixes: 246331e3 ("bpf: allow struct bpf_wq to be embedded in arraymaps and hashmaps")
Signed-off-by: default avatarBenjamin Tissoires <bentiss@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20240430-bpf-next-v3-1-27afe7f3b17c@kernel.org
parent 1bba3b3d

kernel/bpf/arraymap.c

+8 −7
Original line number Diff line number Diff line
@@ -436,14 +436,15 @@ static void array_map_free_timers_wq(struct bpf_map *map) 
	/* We don't reset or free fields other than timer and workqueue

	 * on uref dropping to zero.

	 */

	if (btf_record_has_field(map->record, BPF_TIMER | BPF_WORKQUEUE)) {

		for (i = 0; i < array->map.max_entries; i++) {

			if (btf_record_has_field(map->record, BPF_TIMER))

		for (i = 0; i < array->map.max_entries; i++)

				bpf_obj_free_timer(map->record, array_map_elem_ptr(array, i));



			if (btf_record_has_field(map->record, BPF_WORKQUEUE))

		for (i = 0; i < array->map.max_entries; i++)

				bpf_obj_free_workqueue(map->record, array_map_elem_ptr(array, i));

		}

	}

}



/* Called when map->refcnt goes to zero, either from workqueue or from syscall */

static void array_map_free(struct bpf_map *map)