net: dns: Check recursive pointers for CNAME handling (1500de81) · Commits · Wenxi XU / zephyr

subsys/net/lib/dns/dns_pack.c

+15 −1

Changes for subsys/net/lib/dns/dns_pack.c: 15 added lines, 1 removed line.
Original line number	Diff line number	Diff line
		@@ -6,6 +6,8 @@

		#include <string.h>
		#include <zephyr/net/buf.h>
		#include <zephyr/sys/bitarray.h>
		#include <zephyr/net/dns_resolve.h>

		#include "dns_pack.h"

		@@ -361,10 +363,11 @@ int dns_unpack_response_query(struct dns_msg_t *dns_msg)
		int dns_copy_qname(uint8_t buf, uint16_t len, uint16_t size,
		struct dns_msg_t *dns_msg, uint16_t pos)
		{
		SYS_BITARRAY_DEFINE(visited, DNS_RESOLVER_MAX_BUF_SIZE);
		uint16_t msg_size = dns_msg->msg_size;
		uint8_t *msg = dns_msg->msg;
		uint16_t lb_size;
		int rc = -EINVAL;
		int rc = -EINVAL, ret, prev;

		*len = 0U;

		@@ -388,6 +391,17 @@ int dns_copy_qname(uint8_t buf, uint16_t len, uint16_t size,
		/* See: RFC 1035, 4.1.4. Message compression */
		pos = ((msg[pos] & mask) << 8) + msg[pos + 1];

		ret = sys_bitarray_test_and_set_bit(&visited, pos, &prev);
		if (ret < 0) {
		rc = -EINVAL;
		break;
		}

		if (prev) {
		rc = -ELOOP;
		break;
		}

		continue;
		}