07-21-2011 09:18 AM
I recently upgraded the Hp Secure Shell (T1471AA_A.05.80.002_HP-UX_B.11.23_IA_PA.dep
OpenSSH_5.8p1+sftpfilecontrol-v1.3-hpn13v7, OpenSSL 0.9.8q 2 Dec 2010
HP-UX Secure Shell-A.05.80.002, HP-UX Secure Shell version
We are now seeing problems with several sftp connections where they appear to be hanging when pushing data. We can pull data with no issue. We can log into the remote server but the data put never completes. After a period of time we get the following:
07/21 15:25:41:321569 comms  SESSION>execpipe: killing child 15296
07/21 15:25:41:322286 comms  SESSION>execpipe: waiting for 15296
07/21 15:25:41:325841 comms  SESSION>execpipe: calling old term handler
07/21 15:25:41:325866 comms  SESSION>TERM signal received: exiting
Any ideas what may be causing they connection to hang on sftp put. We have confirmed no issue on the remote server, no network issue.
07-21-2011 09:48 AM
Do you receive the same problem with systems not using 05.80 version of Secure Shell?
You may need to swinstall a different version of Secure Shell to get around this problem.
Have you made any changes lately, customizations to the sshd_config file.
Owner of ISN Corporation
08-23-2011 03:45 PM
Did you guys get to the bottom of this? I'm seeing a hang as well with version "OpenSSH_5.8p2, OpenSSL 0.9.7l 28 Sep 2006". The server is custom.
I tracked it down relatively far but my patience is growing thin. Here is what I found:
The sftp process passes off 32K of the plaintext file in a SSH_FXP_WRITE packet to the ssh process in one large writev. The ssh process is breaking up the 32K into 8K chunks, encrypting them, and presumably sending them all out. The problem is that my server is only receiving 3 of these 8K chunks and all indications are that the server really only did send the three. I was thinking maybe there was something in the SSH spec that called for an ACK from the server but my web search on this turned up a ton of hits on sftp put hangs so maybe there is a client-side bug.