diff options
Diffstat (limited to 'networking/udhcp/common.c')
| -rw-r--r-- | networking/udhcp/common.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/networking/udhcp/common.c b/networking/udhcp/common.c index 0cf4dab63..589bcd674 100644 --- a/networking/udhcp/common.c +++ b/networking/udhcp/common.c @@ -226,9 +226,12 @@ uint8_t* FAST_FUNC udhcp_get_option(struct dhcp_packet *packet, int code) rem = sizeof(packet->options); while (1) { if (rem <= 0) { + complain: bb_error_msg("bad packet, malformed option field"); return NULL; } + + /* DHCP_PADDING and DHCP_END have no [len] byte */ if (optionptr[OPT_CODE] == DHCP_PADDING) { rem--; optionptr++; @@ -251,10 +254,13 @@ uint8_t* FAST_FUNC udhcp_get_option(struct dhcp_packet *packet, int code) } break; } + + if (rem <= OPT_LEN) + goto complain; /* complain and return NULL */ len = 2 + optionptr[OPT_LEN]; rem -= len; if (rem < 0) - continue; /* complain and return NULL */ + goto complain; /* complain and return NULL */ if (optionptr[OPT_CODE] == code) { log_option("option found", optionptr); |