cls_flow: 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 13:47:23 -08:00 committed by David S. Miller
parent ed14816814
commit 22f7cec93f
1 changed files with 18 additions and 6 deletions

View File

@ -372,15 +372,21 @@ static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
[TCA_FLOW_PERTURB] = { .type = NLA_U32 },
};
static void __flow_destroy_filter(struct flow_filter *f)
{
del_timer_sync(&f->perturb_timer);
tcf_exts_destroy(&f->exts);
tcf_em_tree_destroy(&f->ematches);
tcf_exts_put_net(&f->exts);
kfree(f);
}
static void flow_destroy_filter_work(struct work_struct *work)
{
struct flow_filter *f = container_of(work, struct flow_filter, work);
rtnl_lock();
del_timer_sync(&f->perturb_timer);
tcf_exts_destroy(&f->exts);
tcf_em_tree_destroy(&f->ematches);
kfree(f);
__flow_destroy_filter(f);
rtnl_unlock();
}
@ -552,8 +558,10 @@ static int flow_change(struct net *net, struct sk_buff *in_skb,
*arg = fnew;
if (fold)
if (fold) {
tcf_exts_get_net(&fold->exts);
call_rcu(&fold->rcu, flow_destroy_filter);
}
return 0;
err2:
@ -570,6 +578,7 @@ static int flow_delete(struct tcf_proto *tp, void *arg, bool *last)
struct flow_filter *f = arg;
list_del_rcu(&f->list);
tcf_exts_get_net(&f->exts);
call_rcu(&f->rcu, flow_destroy_filter);
*last = list_empty(&head->filters);
return 0;
@ -594,7 +603,10 @@ static void flow_destroy(struct tcf_proto *tp)
list_for_each_entry_safe(f, next, &head->filters, list) {
list_del_rcu(&f->list);
call_rcu(&f->rcu, flow_destroy_filter);
if (tcf_exts_get_net(&f->exts))
call_rcu(&f->rcu, flow_destroy_filter);
else
__flow_destroy_filter(f);
}
kfree_rcu(head, rcu);
}