diff -Naur affix-kernel-old/btcore/hci.c affix-kernel/btcore/hci.c
--- affix-kernel-old/btcore/hci.c	2004-02-20 15:46:54.000000000 +0200
+++ affix-kernel/btcore/hci.c	2005-04-22 14:50:52.000000000 +0300
@@ -2206,7 +2206,7 @@
 
 int affix_sock_register(struct net_proto_family *pf, int protocol)
 {
-	if (protocol >= BTPROTO_MAX)
+	if ((protocol < 0) || (protocol >= BTPROTO_MAX))
 		return -EINVAL;
 	if (btprotos[protocol])
 		return -EEXIST;
@@ -2227,7 +2227,7 @@
 
 int affix_sock_unregister(int protocol)
 {
-	if (protocol >= BTPROTO_MAX)
+	if ((protocol < 0) || (protocol >= BTPROTO_MAX))
 		return -EINVAL;
 	btprotos[protocol] = NULL;
 	return 0;
@@ -2238,7 +2238,7 @@
 	int	i;
 
 	DBFENTER;
-	if (protocol >= BTPROTO_MAX)
+	if ((protocol < 0) || (protocol >= BTPROTO_MAX))
 		return -EPROTONOSUPPORT;
 	if (btprotos[protocol] == NULL) {
 		if (protocol == BTPROTO_RFCOMM)