Comment 20 for bug 2069324

Hello,

I acutally run a shell script /root/foo.sh which runs several commands.
Maybe that is a difference.
And I only use FTPS to connect.

Regards,
Markus

Am 12.07.24 um 09:33 schrieb Christian Ehrhardt :
> Hi,
> first of all thanks for all the prep work.
> The patch LGTM and I agree we should add it.
> I was happy to see the suggestions on how to reproduce, but while writing it out in more detail could not reproduce the hang. The following are the steps I drafted to an SRU templates "how to test and verify" steps. But the hang does not occur. Could you have a look where my steps diverge from what you had in mind?
>
>
> # Install ftp server
> $ sudo apt install vsftpd
>
> # set a user with password, I use ubuntu:ubuntu in the examples here
> $ passwd ubuntu
>
> # add testfile to the users home dir
> $ echo foobar > /home/ubuntu/egal
>
> # Check with FTP if the normal setup works
> root@o:~# ftp 127.0.0.1
> Connected to 127.0.0.1.
> 220 (vsFTPd 3.0.5)
> Name (127.0.0.1:root): ubuntu
> 331 Please specify the password.
> Password:
> 230 Login successful.
> Remote system type is UNIX.
> Using binary mode to transfer files.
> ftp> dir
> 229 Entering Extended Passive Mode (|||47570|)
> 150 Here comes the directory listing.
> -rw-r--r-- 1 0 0 7 Jul 12 06:59 egal
> 226 Directory send OK.
> ftp> get egal
> local: egal remote: egal
> 229 Entering Extended Passive Mode (|||21047|)
> 150 Opening BINARY mode data connection for egal (7 bytes).
> 100% |**************************************************************************************************************************************************| 7 45.87 KiB/s 00:00 ETA
> 226 Transfer complete.
> 7 bytes received in 00:00 (8.49 KiB/s)
> ftp> ^D
> 221 Goodbye.
> root@o:~# cat egal
> foobar
> root@o:~# rm egal
>
>
> # Now set up the failure condition
> #1 add a few exec commands on pam
> $ echo "account optional pam_exec.so debug quiet /bin/true" | sudo tee -a /etc/pam.d/vsftpd
>
> # Restart server to be sure to pick up everything
> $ sudo systemctl restart vsftpd.service
>
> # Log in again to see the hang
> $ ftp 127.0.0.1
>
> ^^ but this does not fall into the hang, I can get the file and quit
> normally.
>
> It is not that the setup is totally useless, in /var/log/auth.log I see on the login
> 2024-07-12T07:27:01.030634+00:00 o vsftpd: pam_exec(vsftpd:account): Calling /bin/true ...
>
>
> Do you have an advice what you do different to reproduce the issue?
>
>
> P.S. along evaluating this I found many more changes we should apply to our ftp servers. Not all suitable for SRUs, but going forward I want to still improve them. To find the required time for that effort I internally filed SD-1755 to not fall through the cracks forever.
>
> ** Changed in: vsftpd (Ubuntu)
> Status: Triaged => Incomplete
>