netfilter: nf_log: validate nf_logger_find_get()

Sanitize nf_logger_find_get() input parameters, no caller in the tree
passes invalid values.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>

net/netfilter/nf_log.c

@@ -156,6 +156,11 @@ int nf_logger_find_get(int pf, enum nf_log_type type)
 	struct nf_logger *logger;
 	int ret = -ENOENT;
 
+	if (pf >= ARRAY_SIZE(loggers))
+		return -EINVAL;
+	if (type >= NF_LOG_TYPE_MAX)
+		return -EINVAL;
+
 	if (pf == NFPROTO_INET) {
 		ret = nf_logger_find_get(NFPROTO_IPV4, type);
 		if (ret < 0)