From aae2c35ec89252639a97769fa72dbbf8f1cc3107 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Mon, 6 Nov 2017 13:47:21 -0800 Subject: [PATCH] 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 Cc: Jamal Hadi Salim Cc: Jiri Pirko Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/sched/cls_bpf.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c index 037a3ae86829..990eb4d91d54 100644 --- a/net/sched/cls_bpf.c +++ b/net/sched/cls_bpf.c @@ -249,6 +249,7 @@ static int cls_bpf_init(struct tcf_proto *tp) 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 @@ static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog) 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 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb, 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); -- 2.20.1