net: dhcp6: Fix OPT_BOOTFILE_PARAM parsing
RFC 5970 states that OPT_BOOTFILE_PARAM (option 60) can be
multiple parameters that start with a 16-bit length field followed
by the parameter. For example:
[ param-len 1 (16-bits) ] [ parameter 1 (variable length) ]
This fix ensure we're considering "param-len 1" in the parsing.
Signed-off-by: Sean Edmond <seanedmond@microsoft.com>
diff --git a/net/dhcpv6.c b/net/dhcpv6.c
index 73a1067..4aea779 100644
--- a/net/dhcpv6.c
+++ b/net/dhcpv6.c
@@ -304,7 +304,7 @@
static void dhcp6_parse_options(uchar *rx_pkt, unsigned int len)
{
uchar *option_ptr;
- int sol_max_rt_sec, option_len;
+ int sol_max_rt_sec, option_len, param_len_1;
char *s, *e;
struct dhcp6_option_hdr *option_hdr;
@@ -390,14 +390,23 @@
case DHCP6_OPTION_OPT_BOOTFILE_PARAM:
if (IS_ENABLED(CONFIG_DHCP6_PXE_DHCP_OPTION)) {
debug("DHCP6_OPTION_OPT_BOOTFILE_PARAM FOUND\n");
+ /* if CONFIG_DHCP6_PXE_DHCP_OPTION is set the PXE config file path
+ * is contained in the first OPT_BOOTFILE_PARAM argument
+ */
+ param_len_1 = ntohs(*((u16 *)option_ptr));
+ option_ptr += sizeof(u16);
+ if (param_len_1 + sizeof(u16) > option_len) {
+ debug("Invalid BOOTFILE_PARAM param_len_1. Skipping\n");
+ break;
+ }
if (pxelinux_configfile)
free(pxelinux_configfile);
- pxelinux_configfile = (char *)malloc((option_len + 1) *
+ pxelinux_configfile = (char *)malloc((param_len_1 + 1) *
sizeof(char));
if (pxelinux_configfile)
- strlcpy(pxelinux_configfile, option_ptr, option_len + 1);
+ strlcpy(pxelinux_configfile, option_ptr, param_len_1 + 1);
else
printf("Error: Failed to allocate pxelinux_configfile\n");