rc/vmz
1
0
Fork 0
Code Issues 33 Pull requests 3 Projects Releases Packages Wiki Activity Actions

Do not treat quit-key bytes as commands for non-interactive stdin #47

New issue
Open
opened 2026-05-22 13:05:33 +00:00 by rc · 0 comments
rc commented 2026-05-22 13:05:33 +00:00
Owner
Copy link

Finding:
The input forwarding loop always interprets quit_key, even when stdin is not a TTY and raw terminal mode was never enabled.

Problem:

  • Raw mode is gated by isatty, but startForwardingInput always runs.
  • forwardInputLoop scans every input byte for active_quit_key and calls stopVirtualMachineFromConsole.

Impact:
With redirected or piped stdin, a literal byte 0x1d is consumed as a host escape instead of being delivered to the guest. This makes automation and binary/fixture input lossy and surprising.

Suggested fix:
Only enable escape-key handling for interactive TTY input, or add an explicit way to disable the escape key. Non-interactive input should be forwarded byte-for-byte and should close the guest input pipe on EOF.

Relevant code:

  • src/vmz.zig: raw terminal setup and input forwarding loop.
Finding: The input forwarding loop always interprets `quit_key`, even when stdin is not a TTY and raw terminal mode was never enabled. Problem: - Raw mode is gated by `isatty`, but `startForwardingInput` always runs. - `forwardInputLoop` scans every input byte for `active_quit_key` and calls `stopVirtualMachineFromConsole`. Impact: With redirected or piped stdin, a literal byte `0x1d` is consumed as a host escape instead of being delivered to the guest. This makes automation and binary/fixture input lossy and surprising. Suggested fix: Only enable escape-key handling for interactive TTY input, or add an explicit way to disable the escape key. Non-interactive input should be forwarded byte-for-byte and should close the guest input pipe on EOF. Relevant code: - `src/vmz.zig`: raw terminal setup and input forwarding loop.
Sign in to join this conversation.
No Branch/Tag specified
Branches Tags
main
codex/verbose-logging
codex-fix-run-without-initrd
codex-package-libvmz
swfit
output
No results found.
Labels
Clear labels   
highprio

   
lowprio
No labels
highprio
lowprio
Milestone
Clear milestone
No items
No milestone
Projects
Clear projects
No items
No project
Assignees
Clear assignees
No assignees
1 participant
Notifications
Due date
The due date is invalid or out of range. Please use the format "yyyy-mm-dd".

No due date set.

Dependencies

No dependencies set.

Reference
rc/vmz#47
No description provided.