static int udhcp_raw_socket(int ifindex)
{
	int fd;
	struct sockaddr_ll sock;

	log1("Opening raw socket on ifindex %d", ifindex); //log2?

	fd = xsocket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
	/* ^^^^^
	 * SOCK_DGRAM: remove link-layer headers on input (SOCK_RAW keeps them)
	 * ETH_P_IP: want to receive only packets with IPv4 eth type
	 */
	log1("Got raw socket fd"); //log2?

	sock.sll_family = AF_PACKET;
	sock.sll_protocol = htons(ETH_P_IP);
	sock.sll_ifindex = ifindex;
	xbind(fd, (struct sockaddr *) &sock, sizeof(sock));

#if 0 /* Several users reported breakage when BPF filter is used */
	if (CLIENT_PORT == 68) {
		/* Use only if standard port is in use */
		/*
		 *	I've selected not to see LL header, so BPF doesn't see it, too.
		 *	The filter may also pass non-IP and non-ARP packets, but we do
		 *	a more complete check when receiving the message in userspace.
		 *
		 * and filter shamelessly stolen from:
		 *
		 *	http://www.flamewarmaster.de/software/dhcpclient/
		 *
		 * There are a few other interesting ideas on that page (look under
		 * "Motivation").  Use of netlink events is most interesting.  Think
		 * of various network servers listening for events and reconfiguring.
		 * That would obsolete sending HUP signals and/or make use of restarts.
		 *
		 * Copyright: 2006, 2007 Stefan Rompf <sux@loplof.de>.
		 * License: GPL v2.
		 */
		static const struct sock_filter filter_instr[] = {
			/* load 9th byte (protocol) */
			BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9),
			/* jump to L1 if it is IPPROTO_UDP, else to L4 */
			BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 0, 6),
			/* L1: load halfword from offset 6 (flags and frag offset) */
			BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 6),
			/* jump to L4 if any bits in frag offset field are set, else to L2 */
			BPF_JUMP(BPF_JMP|BPF_JSET|BPF_K, 0x1fff, 4, 0),
			/* L2: skip IP header (load index reg with header len) */
			BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0),
			/* load udp destination port from halfword[header_len + 2] */
			BPF_STMT(BPF_LD|BPF_H|BPF_IND, 2),
			/* jump to L3 if udp dport is CLIENT_PORT, else to L4 */
			BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1),
			/* L3: accept packet ("accept 0x7fffffff bytes") */
			/* Accepting 0xffffffff works too but kernel 2.6.19 is buggy */
			BPF_STMT(BPF_RET|BPF_K, 0x7fffffff),
			/* L4: discard packet ("accept zero bytes") */
			BPF_STMT(BPF_RET|BPF_K, 0),
		};
		static const struct sock_fprog filter_prog = {
			.len = sizeof(filter_instr) / sizeof(filter_instr[0]),
			/* casting const away: */
			.filter = (struct sock_filter *) filter_instr,
		};
		/* Ignoring error (kernel may lack support for this) */
		if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog,
				sizeof(filter_prog)) >= 0)
			log1("Attached filter to raw socket fd"); // log?
	}
#endif

	if (setsockopt_1(fd, SOL_PACKET, PACKET_AUXDATA) != 0) {
		if (errno != ENOPROTOOPT)
			log1("Can't set PACKET_AUXDATA on raw socket");
	}

	log1("Created raw socket");

	return fd;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.