From e7dabb14f7c8fd9bd2bea55d8f1accc65323a1c0 Mon Sep 17 00:00:00 2001 From: David Cermak Date: Tue, 7 Sep 2021 13:05:38 +0200 Subject: [PATCH] mdns: Fix potential null dereference identified by fuzzer tests --- components/mdns/mdns.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/components/mdns/mdns.c b/components/mdns/mdns.c index 417b01fe0f..7045c76bc7 100644 --- a/components/mdns/mdns.c +++ b/components/mdns/mdns.c @@ -2775,7 +2775,8 @@ static bool _mdns_question_matches(mdns_parsed_question_t * question, uint16_t t } } else if (service && (type == MDNS_TYPE_SRV || type == MDNS_TYPE_TXT)) { const char * name = _mdns_get_service_instance_name(service->service); - if (name && question->host && !strcasecmp(name, question->host) + if (name && question->host && question->service && question->proto && question->domain + && !strcasecmp(name, question->host) && !strcasecmp(service->service->service, question->service) && !strcasecmp(service->service->proto, question->proto) && !strcasecmp(MDNS_DEFAULT_DOMAIN, question->domain)) { @@ -3237,7 +3238,7 @@ void mdns_parse_packet(mdns_rx_packet_t * packet) } else if (service) { // only detect srv collision if service existed col = _mdns_check_srv_collision(service->service, priority, weight, port, name->host, name->domain); } - if (col && (parsed_packet->probe || parsed_packet->authoritative)) { + if (service && col && (parsed_packet->probe || parsed_packet->authoritative)) { if (col > 0 || !port) { do_not_reply = true; if (_mdns_server->interfaces[packet->tcpip_if].pcbs[packet->ip_protocol].probe_running) {