From: James Jones <jejones3141@gmail.com>
Date: Tue, 17 Oct 2023 20:33:00 +0000 (-0500)
Subject: Try to make coverity recognize range check on len (CID #1448182)
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=861765a321badd010023c8bd0ef231c67f7e63c6;p=thirdparty%2Ffreeradius-server.git

Try to make coverity recognize range check on len (CID #1448182)
---

diff --git a/src/listen/dhcpv6/proto_dhcpv6.c b/src/listen/dhcpv6/proto_dhcpv6.c
index 479a4da5c2b..6906ee081f8 100644
--- a/src/listen/dhcpv6/proto_dhcpv6.c
+++ b/src/listen/dhcpv6/proto_dhcpv6.c
@@ -324,8 +324,7 @@ static ssize_t mod_encode(UNUSED void const *instance, request_t *request, uint8
 		client_id = fr_dhcpv6_option_find(request->packet->data + 4, request->packet->data + request->packet->data_len, attr_client_id->attr);
 		if (client_id) {
 			size_t len = fr_nbo_to_uint16(client_id + 2);
-			if ((data_len + 4 + len) <= buffer_len) {
-				/* coverity[tainted_data] */
+			if (len <= (buffer_len - (data_len + 4))) {
 				memcpy(buffer + data_len, client_id, 4 + len);
 				data_len += 4 + len;
 			}