From: Alan T. DeKok <aland@freeradius.org>
Date: Sun, 17 Jan 2021 15:12:05 +0000 (-0500)
Subject: check for empty packets
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=24a9d80a87641ffac2193c0e0550206ceb95455a;p=thirdparty%2Ffreeradius-server.git

check for empty packets
---

diff --git a/src/protocols/dhcpv6/base.c b/src/protocols/dhcpv6/base.c
index 1871c7f56d8..ed5b4a35fbd 100644
--- a/src/protocols/dhcpv6/base.c
+++ b/src/protocols/dhcpv6/base.c
@@ -229,6 +229,11 @@ static ssize_t fr_dhcpv6_ok_internal(uint8_t const *packet, uint8_t const *end,
 	bool		allow_relay;
 	size_t		packet_len = end - packet;
 
+	if (end == packet) {
+		fr_strerror_const("Packet is empty");
+		return 0;
+	}
+
 	if (depth > DHCPV6_MAX_RELAY_NESTING) {
 		fr_strerror_const("Too many layers forwarded packets");
 		return 0;
@@ -632,6 +637,8 @@ ssize_t	fr_dhcpv6_decode(TALLOC_CTX *ctx, uint8_t const *packet, size_t packet_l
 	fr_dhcpv6_decode_ctx_t	packet_ctx;
 	fr_pair_t		*vp;
 
+	if (!packet_len) return 0; /* protect access to packet[0] */
+
 	/*
 	 *	Get the packet type.
 	 */