`PtrRecord::ReadPtrName()` reads a PTR target's first label with
`Name::ReadLabel()`, which performs no emptiness check. A response whose
first label is a single NUL byte (wire `01 00`) is stored as an empty
C-string and cached by the browse cache as a service instance. When the
cache later builds a known-answer question, it calls
`Name::AppendLabel("")`, which returns `kErrorInvalidArgs`; the
surrounding `SuccessOrAssert()` turns that into an abort. A single
unauthenticated link-local mDNS response thus crashes any node with an
active browser.
Reject an empty first label in `ReadPtrName()` so the record is dropped
on receive and never cached. This matches the `Name::ValidateLabel`
checks already applied on the registration and resolver paths, and makes
the "ReadPtrName() validates that PTR record is well-formed" comment at
the call site accurate.
Add a regression test that delivers a PTR response with a single
NUL-byte instance label and verifies no result is reported and the
browser keeps querying without the malformed entry.
What is OpenThread?
OpenThread released by Google is...
...an open-source implementation of the Thread networking protocol. Google Nest has released OpenThread to make the technology used in Nest products more broadly available to developers to accelerate the development of products for the connected home.
...OS and platform agnostic, with a narrow platform abstraction layer and a small memory footprint, making it highly portable. It supports both system-on-chip (SoC) and network co-processor (NCP) designs.
...a Thread Certified Component, implementing all features defined in the Thread 1.4.0 specification, including all Thread networking layers (IPv6, 6LoWPAN, IEEE 802.15.4 with MAC security, Mesh Link Establishment, Mesh Routing) and device roles, as well as Border Router support.
More information about Thread can be found at threadgroup.org. Thread is a registered trademark of the Thread Group, Inc.
Who supports OpenThread?
Getting started
All end-user documentation and guides are located at openthread.io. If you're looking to do things like...
- Learn more about OpenThread features and enhancements
- Use OpenThread in your products
- Learn how to build and configure a Thread network
- Port OpenThread to a new platform
- Build an application on top of OpenThread
- Certify a product using OpenThread
...then openthread.io is the place for you.
Note: For users in China, end-user documentation is available at openthread.google.cn.
If you're interested in contributing to OpenThread, read on.
Contributing
We would love for you to contribute to OpenThread and help make it even better than it is today! See our Contributing Guidelines for more information.
Contributors are required to abide by our Code of Conduct and Coding Conventions and Style Guide.
License
OpenThread is released under the BSD 3-Clause license. See the LICENSE file for more information.
Please only use the OpenThread name and marks when accurately referencing this software distribution. Do not use the marks in a way that suggests you are endorsed by or otherwise affiliated with Nest, Google, or The Thread Group.
Need help?
OpenThread support is available on GitHub:
- Bugs and feature requests — submit to the Issue Tracker
- Community Discussion - ask questions, share ideas, and engage with other community members























