Comment 28 for bug 1003296

I wrote and tested a patch that fixes the bug. Reading the source code i found that this:

 _pam_log(ctx, LOG_CRIT, "Received [%s] reply from application.\n", resp->resp);

So i searched on the auth.log logfile for this log entry and found:

pam_winbind(lightdm:auth): Received [(null)] reply from application

Then i found on a the crashfile stackthread:

#0 __strcasecmp_l_ssse3 () at ../sysdeps/i386/i686/multiarch/strcmp-ssse3.S:293
 No locals.
 #1 0xb7221398 in _pam_winbind_change_pwd (ctx=<optimized out>) at ../nsswitch/pam_winbind.c:834
         msg = {msg_style = 5, msg = 0xb7228f90 "Do you want to change your password now?"}
         pmsg = 0xbfc39810
         resp = 0x85831a8
         prompt = <optimized out>
         ret = <optimized out>
         retval = false

So the problem is on the call of strcasecmp with null as first parameter.

Attached the patch that fixes the issue.

I tested against the latest sources for precise that can be downloaded with:

apt-get source samba