diff options
| author | Roger Light <roger@atchoo.org> | 2019-01-17 19:06:24 +0000 |
|---|---|---|
| committer | Anders Broman <a.broman58@gmail.com> | 2019-01-18 07:49:12 +0000 |
| commit | 10bcb40c5e9e7248d8b63835425e2f3a88bbea96 (patch) | |
| tree | 48f4455bc2acfa5489a4dedad2851a06a9f398c1 /epan/dissectors/packet-mqtt.c | |
| parent | 362be299d07e68d2c249b2d27e05eebf2c806940 (diff) | |
MQTT v5 malformed packet fixes.
PUBACK, PUBREC, PUBREL, and PUBCOMP can all have abbreviated packets
which are not currently handled, leading to those forms being marked as
malformed.
Bug: 15428
Change-Id: I1e6e5dbbca29e7e731683d5c166f9abf978f62b2
Reviewed-on: https://code.wireshark.org/review/31580
Petri-Dish: Anders Broman <a.broman58@gmail.com>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>
Diffstat (limited to 'epan/dissectors/packet-mqtt.c')
| -rw-r--r-- | epan/dissectors/packet-mqtt.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/epan/dissectors/packet-mqtt.c b/epan/dissectors/packet-mqtt.c index 4939e2eddc..ec1bda793a 100644 --- a/epan/dissectors/packet-mqtt.c +++ b/epan/dissectors/packet-mqtt.c @@ -1205,12 +1205,22 @@ static int dissect_mqtt(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, voi offset += 2; col_append_fstr(pinfo->cinfo, COL_INFO, " (id=%u)", mqtt_msgid); - if (mqtt->runtime_proto_version == MQTT_PROTO_V50) + /* MQTT v5.0: The Reason Code and Property Length can be omitted if the + * Reason Code is 0x00 and there are no Properties. + * In this case, the PUB* has a Remaining Length of 2. + */ + if (mqtt->runtime_proto_version == MQTT_PROTO_V50 && mqtt_msg_len > 2) { dissect_mqtt_reason_code(mqtt_tree, tvb, offset, mqtt_msg_type); offset += 1; - offset += dissect_mqtt_properties(tvb, mqtt_tree, offset, hf_mqtt_property); + /* If the Remaining Length is less than 4, the Property Length is not + * present and has a value of 0. + */ + if (mqtt_msg_len > 3) + { + offset += dissect_mqtt_properties(tvb, mqtt_tree, offset, hf_mqtt_property); + } } break; |