From c426914fa166ffb0482b6f6ad659ddf17d5dfaa1 Mon Sep 17 00:00:00 2001
From: Nir Soffer <nsoffer@redhat.com>
Date: Wed, 9 Jan 2019 23:41:16 +0200
Subject: [PATCH] pam_lastlog: Improve silent option documentation

The silent option explicitly silents only the last login message and not
bad logins. Add a note to the manual to make this clear.

* modules/pam_lastlog/pam_lastlog.8.xml: Clearify "silent showfailed"
---
 modules/pam_lastlog/pam_lastlog.8.xml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/modules/pam_lastlog/pam_lastlog.8.xml b/modules/pam_lastlog/pam_lastlog.8.xml
index c8f247e..bc2e1be 100644
--- a/modules/pam_lastlog/pam_lastlog.8.xml
+++ b/modules/pam_lastlog/pam_lastlog.8.xml
@@ -102,6 +102,7 @@
           <para>
             Don't inform the user about any previous login,
             just update the <filename>/var/log/lastlog</filename> file.
+            This option does not affect display of bad login attempts.
           </para>
         </listitem>
       </varlistentry>
-- 
2.20.1

From 7d036249a9772c546ede1f38ad68b3f1575216d6 Mon Sep 17 00:00:00 2001
From: Nir Soffer <nsoffer@redhat.com>
Date: Sun, 6 Jan 2019 00:36:27 +0200
Subject: [PATCH] pam_lastlog: Respect PAM_SILENT flag

pam_lastlog module will not log info about failed login if the session
was opened with PAM_SILENT flag.

Example use case enabled by this change:

    sudo --non-interactive program

If this command is run by another program expecting specific output from
the command run by sudo, the unexpected info about failed logins will
break this program.

* modules/pam_lastlog/pam_lastlog.c: Respect silent option.
  (_pam_session_parse): Unset LASTLOG_BTMP if PAM_SILENT is set.
---
 modules/pam_lastlog/pam_lastlog.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/modules/pam_lastlog/pam_lastlog.c b/modules/pam_lastlog/pam_lastlog.c
index 18bf7be..e980c04 100644
--- a/modules/pam_lastlog/pam_lastlog.c
+++ b/modules/pam_lastlog/pam_lastlog.c
@@ -135,11 +135,6 @@ _pam_session_parse(pam_handle_t *pamh, int flags, int argc, const char **argv)
 {
     int ctrl=(LASTLOG_DATE|LASTLOG_HOST|LASTLOG_LINE|LASTLOG_WTMP|LASTLOG_UPDATE);
 
-    /* does the appliction require quiet? */
-    if (flags & PAM_SILENT) {
-	ctrl |= LASTLOG_QUIET;
-    }
-
     /* step through arguments */
     for (; argc-- > 0; ++argv) {
 
@@ -168,6 +163,12 @@ _pam_session_parse(pam_handle_t *pamh, int flags, int argc, const char **argv)
 	}
     }
 
+    /* does the appliction require quiet? */
+    if (flags & PAM_SILENT) {
+	ctrl |= LASTLOG_QUIET;
+	ctrl &= ~LASTLOG_BTMP;
+    }
+
     D(("ctrl = %o", ctrl));
     return ctrl;
 }
-- 
2.20.1