Binary data can trigger a cpptools infinite loop

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#14,723 4 comments 0 reactions 1 assignee View on GitHub

@sean-mcmanus is already working on this.

Since Sep 1, 2026.

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Description

bug Language Service more info needed
Environment
  • OS and Version: MacOS 26, using a container running Ubuntu 24.04.4 LTS
  • VS Code Version: 1.135.0 (Universal)
  • C/C++ Extension Version: 0.6.18
  • If using SSH remote, specify OS of remote machine:
Bug Summary and Steps to Reproduce

Bug Summary:

I have a file that, when placed in a directory within a workspace that uses cpptools, causes cpptools-srv2 to get stuck in an apparent infinite loop. I've redacted the file so that it's mostly NULs. In fact, strings things it has no text at all.

Steps to reproduce:

  1. Make sure that the C++ extension is installed.
  2. Extract the attached file. Name it testfile (or probably just about anything else).
  3. Check your CPU usage.

I believe this is not a security issue with any meaningful impact, as (as far as I know) it's only triggerable by placing the offending content into a non-restricted-mode workspace, and it's straightforward to get actual code execution in this context using ordinary configuration. It is, however, a kind of annoying functionality bug, since I have repeatedly triggered it by accident.

testfile.gz

FWIW, there is very little content in that file. I managed to reduce it to a file that's kind of large but has almost as little complexity as one could imagine. I did not try to reduce it to a smaller file.

Configuration and Logs
There is no relevant configuration.  The log says:


LSP: (received) cpptools/fileCreated: file:///workspaces/master/testfile
LSP: (invoked) cpptools/fileCreated: file:///workspaces/master/testfile
Initiating store rescan...
Other Extensions

No response

Additional context

No response

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