Created attachment 11208 [details]
possible fix

I'm running Samba 4.2.2 on OmniOS r151014 and I find that when samba is joined to one of our domains (we use windows 2012r2 domain controllers) it can't authenticate users in that domain, failing with this error:

[2015/06/24 17:49:52.718039,  0, pid=3060, effective(0, 0), real(0, 0), class=auth] ../source3/auth/auth_domain.c:302(domain_client_validate)
  domain_client_validate: unable to validate password for user xjono in domain LABS to Domain controller LAVENDER.LABS.EAIT.UQ.EDU.AU. Error was NT_STATUS_LOCK_NOT_GRANTED.

This turns out to be because the struct netlogon_creds_cli_context allocated in connect_to_domain_password_server is allocated in a talloc context that is freed at the end of that function.  The memory allocator on OmniOS seems to reuse freed memory immediately, so in my case the struct netr_NetworkInfo allocated in rpccli_netlogon_network_logon overlaps it, and around line 470 of source3/rpc_client/cli_netlogon.c it writes a pointer where the netlogon_creds_cli_context keeps its locked_state pointer - so netlogon_creds_cli_LogonSamLogon, called immediately afterwards, fails with the LOCK_NOT_GRANTED error because it thinks the context is already locked.

The patch I'm attaching moves the netlogon_creds_cli_context into the talloc context provided to domain_client_validate, which ensures it lives long enough.  I haven't tested this extensively but it fixes the immediate problem for me.