IV82042: sshd hangs due to a race condition involving ptys

APAR status

• Closed as fixed if next.

Error description

• When ssh is executed with ptty enabled, hang is seen due
  to race conditions. Typical hang occurs at location:
  debug1: Entering interactive session.
  debug2: callback start
  debug2: client_session2_setup: id 0
  debug3: packet_set_tos: set IP_TOS 0x10
  debug2: channel 0: request pty-req confirm 1
  debug1: Sending command: /bin/sh -c date
  debug2: channel 0: request exec confirm 1
  debug2: callback done
  debug2: channel 0: open confirm rwindow 0 rmax 32768
  
  Although there could be couple of other prints after this
  message and then hang appears.
  

Local fix

• There is no known work around
  

Problem summary

• ssh would sometimes hang while connecting, leaving around
  orphaned sshd processes
  

Problem conclusion

Temporary fix

• Update to latest version of openssh.
  

Comments

• This APAR is being closed FIN. This means that a solution to
  this APAR is expected to be delivered from IBM in a release
  (if any) to be available within the next 24 months.
  

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

Applicable component levels