NEX-2842 SMB client authentication fails in adt_set_user() with IDMU enabled

*** 19,28 ****
--- 19,29 ----
   * CDDL HEADER END
   */
  
  /*
   * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
+  * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
   * Copyright 2017 OmniOS Community Edition (OmniOSce) Association.
   */
  
  #include <bsm/adt.h>
  #include <bsm/adt_event.h>
*** 189,219 ****
  
          if (auditstate & AUC_DISABLED) {
                  /* c2audit excluded */
                  mask->am_success = 0;
                  mask->am_failure = 0;
!         } else if (uid <= MAXUID) {
                  if ((buff_sz = sysconf(_SC_GETPW_R_SIZE_MAX)) == -1) {
                          adt_write_syslog("couldn't determine maximum size of "
                              "password buffer", errno);
                          return (-1);
                  }
                  if ((pwd_buff = calloc(1, (size_t)++buff_sz)) == NULL) {
                          return (-1);
                  }
!                 if (getpwuid_r(uid, &pwd, pwd_buff, (int)buff_sz) == NULL) {
!                         errno = EINVAL; /* user doesn't exist */
!                         free(pwd_buff);
!                         return (-1);
!                 }
                  if (au_user_mask(pwd.pw_name, mask)) {
                          free(pwd_buff);
                          errno = EFAULT; /* undetermined failure */
                          return (-1);
                  }
                  free(pwd_buff);
!         } else if (auditon(A_GETKMASK, (caddr_t)mask, sizeof (*mask)) == -1) {
                          return (-1);
          }
  
          return (0);
  }
--- 190,229 ----
  
          if (auditstate & AUC_DISABLED) {
                  /* c2audit excluded */
                  mask->am_success = 0;
                  mask->am_failure = 0;
!                 return (0);
!         }
! 
!         if (uid <= MAXUID) {
                  if ((buff_sz = sysconf(_SC_GETPW_R_SIZE_MAX)) == -1) {
                          adt_write_syslog("couldn't determine maximum size of "
                              "password buffer", errno);
                          return (-1);
                  }
                  if ((pwd_buff = calloc(1, (size_t)++buff_sz)) == NULL) {
                          return (-1);
                  }
!                 /*
!                  * Ephemeral id's and id's that exist in a name service we
!                  * don't have configured (LDAP, NIS) can't be looked up,
!                  * but either way it's not an error.
!                  */
!                 if (getpwuid_r(uid, &pwd, pwd_buff, (int)buff_sz) != NULL) {
                          if (au_user_mask(pwd.pw_name, mask)) {
                                  free(pwd_buff);
                                  errno = EFAULT; /* undetermined failure */
                                  return (-1);
                          }
                          free(pwd_buff);
!                         return (0);
!                 }
!                 free(pwd_buff);
!         }
! 
!         if (auditon(A_GETKMASK, (caddr_t)mask, sizeof (*mask)) == -1) {
                          return (-1);
          }
  
          return (0);
  }