Copssh version 5.0.4 comes with a custom patch addressing session hang problems during logout for domain users. Users experiencing the problem reported that they observe following lines in the event log:

error: chmod /dev/pty1 0666 failed: No such file or directory

error: chown /dev/pty1 0 0 failed: No such file or directory

As a result of that failure, you may observe multiple hanging sshd processes at the server side as well. Please upgrade if you experience those problems in your environment.

Contents of the custom patch:

--- sshpty.c 2014-05-21 09:06:47.000000000 +0200+++ sshpty.new.c 2015-03-06 17:26:49.125000000 +0100@@ -85,12 +85,7 @@ void pty_release(const char *tty) {-#ifndef __APPLE_PRIVPTY__- if (chown(tty, (uid_t) 0, (gid_t) 0) < 0)- error("chown %.100s 0 0 failed: %.100s", tty, strerror(errno));- if (chmod(tty, (mode_t) 0666) < 0)- error("chmod %.100s 0666 failed: %.100s", tty, strerror(errno));-#endif /* __APPLE_PRIVPTY__ */+ return; }  /* Makes the tty the process's controlling tty and sets it to sane modes. */