netfilter: ctnetlink: drop the incorrect cthelper module request

First, when creating a new ct, we will invoke request_module to try to
load the related inkernel cthelper. So there's no need to call the
request_module again when updating the ct helpinfo.

Second, ctnetlink_change_helper may be called with rcu_read_lock held,
i.e. rcu_read_lock -> nfqnl_recv_verdict -> nfqnl_ct_parse ->
ctnetlink_glue_parse -> ctnetlink_glue_parse_ct ->
ctnetlink_change_helper. But the request_module invocation may sleep,
so we can't call it with the rcu_read_lock held.

Remove it now.

Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Liping Zhang 2017-04-17 21:18:55 +08:00 committed by Pablo Neira Ayuso
parent 54a5f9d9ab
commit 14e5676156

View File

@ -1512,23 +1512,8 @@ static int ctnetlink_change_helper(struct nf_conn *ct,
helper = __nf_conntrack_helper_find(helpname, nf_ct_l3num(ct),
nf_ct_protonum(ct));
if (helper == NULL) {
#ifdef CONFIG_MODULES
spin_unlock_bh(&nf_conntrack_expect_lock);
if (request_module("nfct-helper-%s", helpname) < 0) {
spin_lock_bh(&nf_conntrack_expect_lock);
return -EOPNOTSUPP;
}
spin_lock_bh(&nf_conntrack_expect_lock);
helper = __nf_conntrack_helper_find(helpname, nf_ct_l3num(ct),
nf_ct_protonum(ct));
if (helper)
return -EAGAIN;
#endif
if (helper == NULL)
return -EOPNOTSUPP;
}
if (help) {
if (help->helper == helper) {