Correctly restoring channel's FDs nonblocking mode #246
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
OpenSSH incorrectly restores the standard mode (blocking mode) on standard output upon exiting. This causes the next shell scripts commands to potentially fail in EAGAIN.
The reproducer is:
#!/bin/sh
(
ssh localhost true
cat /dev/zero
) | sleep 30
Restoring the blocking modes happens with the duped file descriptors and too late.
The changes causing this problem was introduced in 4d5456c
The previous patches was provided in #244
This is an alternate approach to fix this problem provided by Masaki Kimura