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>
This commit is contained in:
Cong Wang 2017-11-06 13:47:21 -08:00 committed by David S. Miller
parent 0b2a59894b
commit aae2c35ec8
1 changed files with 6 additions and 1 deletions

View File

@ -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);