cls_route: 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 13:47:27 -08:00 committed by David S. Miller
parent 57767e7853
commit 3fd51de5e3
1 changed files with 14 additions and 3 deletions

View File

@ -257,13 +257,19 @@ static int route4_init(struct tcf_proto *tp)
return 0;
}
static void __route4_delete_filter(struct route4_filter *f)
{
tcf_exts_destroy(&f->exts);
tcf_exts_put_net(&f->exts);
kfree(f);
}
static void route4_delete_filter_work(struct work_struct *work)
{
struct route4_filter *f = container_of(work, struct route4_filter, work);
rtnl_lock();
tcf_exts_destroy(&f->exts);
kfree(f);
__route4_delete_filter(f);
rtnl_unlock();
}
@ -297,7 +303,10 @@ static void route4_destroy(struct tcf_proto *tp)
next = rtnl_dereference(f->next);
RCU_INIT_POINTER(b->ht[h2], next);
tcf_unbind_filter(tp, &f->res);
call_rcu(&f->rcu, route4_delete_filter);
if (tcf_exts_get_net(&f->exts))
call_rcu(&f->rcu, route4_delete_filter);
else
__route4_delete_filter(f);
}
}
RCU_INIT_POINTER(head->table[h1], NULL);
@ -338,6 +347,7 @@ static int route4_delete(struct tcf_proto *tp, void *arg, bool *last)
/* Delete it */
tcf_unbind_filter(tp, &f->res);
tcf_exts_get_net(&f->exts);
call_rcu(&f->rcu, route4_delete_filter);
/* Strip RTNL protected tree */
@ -541,6 +551,7 @@ static int route4_change(struct net *net, struct sk_buff *in_skb,
*arg = f;
if (fold) {
tcf_unbind_filter(tp, &fold->res);
tcf_exts_get_net(&fold->exts);
call_rcu(&fold->rcu, route4_delete_filter);
}
return 0;