cls_fw: 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 13:47:25 -08:00 committed by David S. Miller
parent 0dadc117ac
commit d5f984f5af
1 changed files with 14 additions and 3 deletions

View File

@ -122,13 +122,19 @@ static int fw_init(struct tcf_proto *tp)
return 0;
}
static void __fw_delete_filter(struct fw_filter *f)
{
tcf_exts_destroy(&f->exts);
tcf_exts_put_net(&f->exts);
kfree(f);
}
static void fw_delete_filter_work(struct work_struct *work)
{
struct fw_filter *f = container_of(work, struct fw_filter, work);
rtnl_lock();
tcf_exts_destroy(&f->exts);
kfree(f);
__fw_delete_filter(f);
rtnl_unlock();
}
@ -154,7 +160,10 @@ static void fw_destroy(struct tcf_proto *tp)
RCU_INIT_POINTER(head->ht[h],
rtnl_dereference(f->next));
tcf_unbind_filter(tp, &f->res);
if (tcf_exts_get_net(&f->exts))
call_rcu(&f->rcu, fw_delete_filter);
else
__fw_delete_filter(f);
}
}
kfree_rcu(head, rcu);
@ -179,6 +188,7 @@ static int fw_delete(struct tcf_proto *tp, void *arg, bool *last)
if (pfp == f) {
RCU_INIT_POINTER(*fp, rtnl_dereference(f->next));
tcf_unbind_filter(tp, &f->res);
tcf_exts_get_net(&f->exts);
call_rcu(&f->rcu, fw_delete_filter);
ret = 0;
break;
@ -299,6 +309,7 @@ static int fw_change(struct net *net, struct sk_buff *in_skb,
RCU_INIT_POINTER(fnew->next, rtnl_dereference(pfp->next));
rcu_assign_pointer(*fp, fnew);
tcf_unbind_filter(tp, &f->res);
tcf_exts_get_net(&f->exts);
call_rcu(&f->rcu, fw_delete_filter);
*arg = fnew;