INN commit: trunk (4 files)

[INN Commit]

    Date: Sunday, January 10, 2016 @ 06:58:42
  Author: iulius
Revision: 9980

rnews:  fix a segfault while starting setuid news

It is a regression introduced with commit [9854].  Previously, rnews
called get_news_uid_gid() that handled the possibility of inn.conf
not having been read.  Since that commit, rnews has been calling
ensure_news_user() that does not handle that case.
Especially, when --enable-uucp-rnews was used at configure time, the
effective UID returned by geteuid() was not root, and rnews segfaulted.

Thanks to Marcus Jodorf for the bug report.

Modified:
  trunk/CONTRIBUTORS
  trunk/doc/pod/news.pod
  trunk/frontends/rnews.c
  trunk/lib/newsuser.c

-------------------+
 CONTRIBUTORS      |    2 +-
 doc/pod/news.pod  |    5 +++++
 frontends/rnews.c |    9 ++++++++-
 lib/newsuser.c    |    9 ++++++---
 4 files changed, 20 insertions(+), 5 deletions(-)

Modified: CONTRIBUTORS
===================================================================
--- CONTRIBUTORS	2015-12-11 20:40:29 UTC (rev 9979)
+++ CONTRIBUTORS	2016-01-10 14:58:42 UTC (rev 9980)
@@ -276,5 +276,5 @@
 Edmund H. Ramm, Raphael Barrois, Bo Lindbergh, Matthias Meyser,
 Dennis Preiser, Paolo Amoroso, Dennis Davis, River Tarnell, Jochen Schmitt,
 Tim Fardell, Remco Rijnders, David Binderman, Tony Evans, Christian Garbs,
-Jesse Rehmer, Colin Watson, Lauri Tirkkonen, Christian Mock,
+Jesse Rehmer, Colin Watson, Lauri Tirkkonen, Christian Mock, Marcus Jodorf,
 Richard Kettlewell

Modified: doc/pod/news.pod
===================================================================
--- doc/pod/news.pod	2015-12-11 20:40:29 UTC (rev 9979)
+++ doc/pod/news.pod	2016-01-10 14:58:42 UTC (rev 9980)
@@ -21,6 +21,11 @@
 
 =item *
 
+B<rnews> no longer segfaults at startup when started setuid news.
+Thanks to Marcus Jodorf for the bug report.
+
+=item *
+
 When an encryption layer is negotiated during a successful use of the
 STARTTLS command, or after a successful authentication using a SASL
 mechanism which negotiates an encryption layer, B<nnrpd> now updates

Modified: frontends/rnews.c
===================================================================
--- frontends/rnews.c	2015-12-11 20:40:29 UTC (rev 9979)
+++ frontends/rnews.c	2016-01-10 14:58:42 UTC (rev 9980)
@@ -861,7 +861,14 @@
        other setups where rnews might be setuid news or be run by other
        processes in the news group. */
     if (getuid() == 0 || geteuid() == 0) {
-        ensure_news_user(true);
+        uid_t uid;
+
+        /* Do not use ensure_news_user() because it will fail to deal
+         * with the case of rnews being setuid news. */
+        get_news_uid_gid(&uid, false, true);
+        if (setuid(uid) < 0) {
+            sysdie("failed to setuid");
+        }
     }
 
     if (!innconf_read(NULL))

Modified: lib/newsuser.c
===================================================================
--- lib/newsuser.c	2015-12-11 20:40:29 UTC (rev 9979)
+++ lib/newsuser.c	2016-01-10 14:58:42 UTC (rev 9980)
@@ -69,7 +69,8 @@
     if (geteuid() == 0) {
         if (! may_setuid) {
             /* NB:  mustn't be run as root, unless "may_setuid" is true. */
-            die("must be run as %s, not as root", innconf->runasuser);
+            die("must be run as %s, not as root",
+                innconf != NULL ? innconf->runasuser : RUNASUSER);
         }
         if (setuid(uid) < 0) {
             sysdie("failed to setuid");
@@ -76,7 +77,8 @@
         }
     }
     if (geteuid() != uid || getuid() != uid) {
-        die("must be run as %s", innconf->runasuser);
+        die("must be run as %s",
+            innconf != NULL ? innconf->runasuser : RUNASUSER);
     }
 }
 
@@ -95,7 +97,8 @@
         }
     }
     if (getegid() != gid || getgid() != gid) {
-        die ("must be run as %s group", innconf->runasgroup);
+        die ("must be run as %s group",
+             innconf != NULL ? innconf->runasgroup : RUNASGROUP);
     }
 }