bpf: offload: free program id when device disappears
Bound programs are quite useless after their device disappears.
They are simply waiting for reference count to go to zero,
don't list them in BPF_PROG_GET_NEXT_ID by freeing their ID
early.
Note that orphaned offload programs will return -ENODEV on
BPF_OBJ_GET_INFO_BY_FD so user will never see ID 0.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
index 3126e1a..e4f1668 100644
--- a/kernel/bpf/offload.c
+++ b/kernel/bpf/offload.c
@@ -130,6 +130,9 @@ static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
if (offload->dev_state)
WARN_ON(__bpf_offload_ndo(prog, BPF_OFFLOAD_DESTROY, &data));
+ /* Make sure BPF_PROG_GET_NEXT_ID can't find this dead program */
+ bpf_prog_free_id(prog, true);
+
list_del_init(&offload->offloads);
kfree(offload);
prog->aux->offload = NULL;
