dns: fix OOB read on malformed TXT record

9 years ago · 731d4a7049
parent 7e6ce01600
commit 731d4a7049
1 changed files with 6 additions and 0 deletions
--- a/src/app-layer-dns-common.c
+++ b/src/app-layer-dns-common.c
@ -983,6 +983,12 @@ const uint8_t *DNSReponseParse(DNSState *dns_state, const DNSHeader * const dns_
        case DNS_RECORD_TYPE_TXT:
        {
            uint16_t datalen = ntohs(head->len);
+
+            if (datalen == 0) {
+                DNSSetEvent(dns_state, DNS_DECODER_EVENT_MALFORMED_DATA);
+                goto bad_data;
+            }
+
            uint8_t txtlen = *data;
            const uint8_t *tdata = data + 1;