cls_bpf: use tcf_exts_get_net() before call_rcu()
Hold netns refcnt before call_rcu() and release it after
the tcf_exts_destroy() is done.
Note, on ->destroy() path we have to respect the return value
of tcf_exts_get_net(), on other paths it should always return
true, so we don't need to care.
Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
index 037a3ae..990eb4d 100644
--- a/net/sched/cls_bpf.c
+++ b/net/sched/cls_bpf.c
@@ -249,6 +249,7 @@
static void __cls_bpf_delete_prog(struct cls_bpf_prog *prog)
{
tcf_exts_destroy(&prog->exts);
+ tcf_exts_put_net(&prog->exts);
if (cls_bpf_is_ebpf(prog))
bpf_prog_put(prog->filter);
@@ -282,7 +283,10 @@
cls_bpf_stop_offload(tp, prog);
list_del_rcu(&prog->link);
tcf_unbind_filter(tp, &prog->res);
- call_rcu(&prog->rcu, cls_bpf_delete_prog_rcu);
+ if (tcf_exts_get_net(&prog->exts))
+ call_rcu(&prog->rcu, cls_bpf_delete_prog_rcu);
+ else
+ __cls_bpf_delete_prog(prog);
}
static int cls_bpf_delete(struct tcf_proto *tp, void *arg, bool *last)
@@ -516,6 +520,7 @@
if (oldprog) {
list_replace_rcu(&oldprog->link, &prog->link);
tcf_unbind_filter(tp, &oldprog->res);
+ tcf_exts_get_net(&oldprog->exts);
call_rcu(&oldprog->rcu, cls_bpf_delete_prog_rcu);
} else {
list_add_rcu(&prog->link, &head->plist);
