Update util.rb to fix closing of file.

[adamboutcher]

When attempting to close files, the /proc/self loop was trying to close a file being converted to an integer which was causing issues on Fedora 42, this resolved the problem.

Also see puppetlabs/puppet#9552

[adamboutcher]

For people searching this is the error that was flagging:

/usr/share/ruby/vendor_ruby/puppet/util.rb:481:in 'Dir.foreach': Bad file descriptor - closedir (Errno::EBADF)

[silug]

If I understand this code correctly, it's trying to close each numbered file descriptor. The .to_i is likely appropriate, but the file list should be filtered to only include names that consist entirely of digits.

[adamboutcher]

The function to close the file handle should be on the handle and not the handle converted to an integer, the to_i is being filtered in the if statement above?

So for example the code should be:
IO.new('/proc/self/fd/4').close
and not
IO.new(4).close

However I'm not a ruby dev so maybe my understanding of the code is incorrect

[silug]

I think what it is doing is closing all file descriptors other than stdin, stdout, stderr, and whatever fd 3 is. 🙂

It does not use the full path in /proc/self/fd, just the numeric file descriptors. On Linux, scanning /proc/self/fd is a handy way to do that.

[adamboutcher]

I think what it is doing is closing all file descriptors other than stdin, stdout, stderr, and whatever fd 3 is. 🙂

I think that's what is intended but the to_i is possibly getting in the way...

I have Fedora 40 which does work (or silently fails) where as Fedora 42 gives the aforementioned error.
The modification in the PR works on both systems fine or is silently failing.

[silug]

@adamboutcher Could you try adding ${^\d+$}.match?(f) to the condition on line 482? I suspect that will resolve the underlying problem.

The line should probably look like this:

          if %{^\d+$}.match?(f) && f.to_i >= 3

[silug]

To be clear, I think the change should look like this:

diff --git a/lib/puppet/util.rb b/lib/puppet/util.rb
index 06c7b11815..66be0f7da3 100644
--- a/lib/puppet/util.rb
+++ b/lib/puppet/util.rb
@@ -479,7 +479,7 @@ module Util
 
       begin
         Dir.foreach('/proc/self/fd') do |f|
-          if f != '.' && f != '..' && f.to_i >= 3
+          if %{^\d+$}.match?(f) && f.to_i >= 3
             begin
               IO.new(f.to_i).close
             rescue

But I'm not seeing this problem for whatever reason, so I can't easily test it.

[adamboutcher]

Will test it when I'm back in the office on Friday.

…

On Tue, 22 Apr 2025, 6:02 pm Steven Pritchard, ***@***.***> wrote: To be clear, I think the change should look like this: diff --git a/lib/puppet/util.rb b/lib/puppet/util.rb index 06c7b11815..66be0f7da3 100644--- a/lib/puppet/util.rb+++ b/lib/puppet/util.rb@@ -479,7 +479,7 @@ module Util begin Dir.foreach('/proc/self/fd') do |f|- if f != '.' && f != '..' && f.to_i >= 3+ if %{^\d+$}.match?(f) && f.to_i >= 3 begin IO.new(f.to_i).close rescue But I'm not seeing this problem for whatever reason, so I can't easily test it. — Reply to this email directly, view it on GitHub <#39 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAOSVCZUN26B6EAENIWXLAD22ZY3NAVCNFSM6AAAAAB3T4OKVWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDQMRRHE2DQNRYGI> . You are receiving this because you were mentioned.Message ID: ***@***.***> *silug* left a comment (OpenVoxProject/puppet#39) <#39 (comment)> To be clear, I think the change should look like this: diff --git a/lib/puppet/util.rb b/lib/puppet/util.rb index 06c7b11815..66be0f7da3 100644--- a/lib/puppet/util.rb+++ b/lib/puppet/util.rb@@ -479,7 +479,7 @@ module Util begin Dir.foreach('/proc/self/fd') do |f|- if f != '.' && f != '..' && f.to_i >= 3+ if %{^\d+$}.match?(f) && f.to_i >= 3 begin IO.new(f.to_i).close rescue But I'm not seeing this problem for whatever reason, so I can't easily test it. — Reply to this email directly, view it on GitHub <#39 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAOSVCZUN26B6EAENIWXLAD22ZY3NAVCNFSM6AAAAAB3T4OKVWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDQMRRHE2DQNRYGI> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[adamboutcher]

if %{^\d+$}.match?(f) && f.to_i >= 3

I've tried this on Fedora42 and it seems to work, or at least I dont get any errors...
I'll change up and repush.

[nmburgan]

@ekohl Do you see any benefit to adding some of your logic from your other PR here? I think they both accomplish the goal. This one guards against any non-integer FD, but yours specifically filters out the ones we expect. I'm not sure if there are other edge cases we need to consider.

[ekohl]

I don't think this actually resolves it. The file descriptor is the last number. If this avoids the error I think it won't close anything at all anymore. I'd suggest reverting this and applying my patch. See the linked bugzilla for minimal reproducer code

[ekohl]

Based on https://bugzilla.redhat.com/show_bug.cgi?id=2349352#c9 a reproducer to show this broke the code:

#!/usr/bin/env ruby

d = Dir.new('/proc/self/fd')
d.each_child do |f|
  if %{^\d+$}.match?(f) && f.to_i >= 3
    begin
      puts "Closing #{f}"
      IO.new(f.to_i).close
    rescue
      nil
    end
  else
    puts "Not closing #{f}"
  end
end

Running it shows it doesn't close anything anymore:

$ ruby close1.rb
Not closing 0
Not closing 1
Not closing 2
Not closing 3
Not closing 4
Not closing 5

[ekohl]

If you want this to work, it needs to be

Suggested change

	if %{^\d+$}.match?(f) && f.to_i >= 3
	if %r{^\d+$}.match?(f) && f.to_i >= 3

Edit: but then you run into the original issue again, which is that the last file descriptor can't be closed.

[ekohl]

I've opened #42 to properly fix the issue.