[NETFILTER]: nfnetlink: remove duplicate checks in nfnetlink_check_attributes

Remove nfnetlink_check_attributes duplicates message size and callback
id checks. nfnetlink_find_client and nfnetlink_rcv_msg already do
such checks.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/netfilter/nfnetlink.c

@@ -149,17 +149,10 @@ static int
 nfnetlink_check_attributes(struct nfnetlink_subsystem *subsys,
 			   struct nlmsghdr *nlh, struct nfattr *cda[])
 {
-	int min_len;
+	int min_len = NLMSG_SPACE(sizeof(struct nfgenmsg));
 	u_int16_t attr_count;
 	u_int8_t cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type);
 
-	if (unlikely(cb_id >= subsys->cb_count))
-		return -EINVAL;
-
-	min_len = NLMSG_SPACE(sizeof(struct nfgenmsg));
-	if (unlikely(nlh->nlmsg_len < min_len))
-		return -EINVAL;
-
 	attr_count = subsys->cb[cb_id].attr_count;
 	memset(cda, 0, sizeof(struct nfattr *) * attr_count);