From ba6b8de423f8d0dee48d6030288ed81c03ddf9f0 Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Mon, 23 Apr 2018 15:39:23 -0700 Subject: bpf: sockmap, map_release does not hold refcnt for pinned maps Relying on map_release hook to decrement the reference counts when a map is removed only works if the map is not being pinned. In the pinned case the ref is decremented immediately and the BPF programs released. After this BPF programs may not be in-use which is not what the user would expect. This patch moves the release logic into bpf_map_put_uref() and brings sockmap in-line with how a similar case is handled in prog array maps. Fixes: 3d9e952697de ("bpf: sockmap, fix leaking maps with attached but not detached progs") Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann --- kernel/bpf/arraymap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel/bpf/arraymap.c') diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 14750e7c5ee4..027107f4be53 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -476,7 +476,7 @@ static u32 prog_fd_array_sys_lookup_elem(void *ptr) } /* decrement refcnt of all bpf_progs that are stored in this map */ -void bpf_fd_array_map_clear(struct bpf_map *map) +static void bpf_fd_array_map_clear(struct bpf_map *map) { struct bpf_array *array = container_of(map, struct bpf_array, map); int i; @@ -495,6 +495,7 @@ const struct bpf_map_ops prog_array_map_ops = { .map_fd_get_ptr = prog_fd_array_get_ptr, .map_fd_put_ptr = prog_fd_array_put_ptr, .map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem, + .map_release_uref = bpf_fd_array_map_clear, }; static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file, -- cgit v1.2.3