CIFS: Add session setup/logoff capability for SMB2

[Dan Carpenter]

Hello Pavel Shilovsky,

This is a semi-automatic email about new static checker warnings.

The patch 5478f9ba9a34: "CIFS: Add session setup/logoff capability 
for SMB2" from Dec 27, 2011, leads to the following Smatch complaint:

fs/cifs/smb2pdu.c:672 SMB2_sess_setup()
	 warn: variable dereferenced before check 'rsp' (see line 657)

fs/cifs/smb2pdu.c
   656			ses->Suid = rsp->hdr.SessionId;
                                    ^^^^^^^^^^^^^^^^^^
New dereference.

   657			rc = decode_ntlmssp_challenge(rsp->Buffer,
   658					le16_to_cpu(rsp->SecurityBufferLength), ses);
   659		}
   660	
   661		/*
   662		 * BB eventually add code for SPNEGO decoding of NtlmChallenge blob,
   663		 * but at least the raw NTLMSSP case works.
   664		 */
   665		/*
   666		 * No tcon so can't do
   667		 * cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_fail[SMB2...]);
   668		 */
   669		if (rc != 0)
   670			goto ssetup_exit;
   671	
   672		if (rsp == NULL) {
                    ^^^^^^^^^^^
New check.

   673			rc = -EIO;
   674			goto ssetup_exit;

regards,
dan carpenter