slackware-current/source/xap/xscreensaver/xscreensaver.setuid.diff

--- ./driver/setuid.c.orig	2006-02-08 20:28:38.000000000 -0600
+++ ./driver/setuid.c	2006-04-04 16:48:08.000000000 -0500
@@ -1,5 +1,5 @@
 /* setuid.c --- management of runtime privileges.
- * xscreensaver, Copyright (c) 1993-1998, 2005 Jamie Zawinski <jwz@jwz.org>
+ * xscreensaver, Copyright (c) 1993-1998 Jamie Zawinski <jwz@jwz.org>
  *
  * Permission to use, copy, modify, distribute, and sell this software and its
  * documentation for any purpose is hereby granted without fee, provided that
@@ -41,7 +41,7 @@
   struct group *g = 0;
   p = getpwuid (uid);
   g = getgrgid (gid);
-  sprintf (buf, "%.100s/%.100s (%ld/%ld)",
+  sprintf (buf, "%s/%s (%ld/%ld)",
 	   (p && p->pw_name ? p->pw_name : "???"),
 	   (g && g->gr_name ? g->gr_name : "???"),
 	   (long) uid, (long) gid);
@@ -74,50 +74,11 @@
 }
 
 
-/* Returns true if we need to call setgroups().
-
-   Without calling setgroups(), the process will retain any supplementary
-   gids associated with the uid, e.g.:
-
-       % groups root
-       root : root bin daemon sys adm disk wheel
-
-   However, setgroups() can only be called by root, and returns EPERM
-   for other users even if the call would be a no-op (e.g., setting the
-   group list to the current list.)  So, to avoid that spurious error,
-   before calling setgroups() we first check whether the current list
-   of groups contains only one element, our target group.  If so, we
-   don't need to call setgroups().
- */
-static int
-setgroups_needed_p (uid_t target_group)
-{
-  gid_t groups[1024];
-  int n, size;
-  size = sizeof(groups) / sizeof(gid_t);
-  n = getgroups (size - 1, groups);
-  if (n < 0)
-    {
-      char buf [1024];
-      sprintf (buf, "%s: getgroups(%ld, ...)", blurb(), (long int)(size - 1));
-      perror (buf);
-      return 1;
-    }
-  else if (n == 0)            /* an empty list means only egid is in effect. */
-    return 0;
-  else if (n == 1 && groups[0] == target_group)   /* one element, the target */
-    return 0;
-  else                        /* more than one, or the wrong one. */
-    return 1;
-}
-
-
 static int
 set_ids_by_number (uid_t uid, gid_t gid, char **message_ret)
 {
   int uid_errno = 0;
   int gid_errno = 0;
-  int sgs_errno = 0;
   struct passwd *p = getpwuid (uid);
   struct group  *g = getgrgid (gid);
 
@@ -136,11 +97,6 @@
   if (uid == (uid_t) -1) uid = (uid_t) -2;
 
   errno = 0;
-  if (setgroups_needed_p (gid) &&
-      setgroups (1, &gid) < 0)
-    sgs_errno = errno ? errno : -1;
-
-  errno = 0;
   if (setgid (gid) != 0)
     gid_errno = errno ? errno : -1;
 
@@ -148,10 +104,10 @@
   if (setuid (uid) != 0)
     uid_errno = errno ? errno : -1;
 
-  if (uid_errno == 0 && gid_errno == 0 && sgs_errno == 0)
+  if (uid_errno == 0 && gid_errno == 0)
     {
       static char buf [1024];
-      sprintf (buf, "changed uid/gid to %.100s/%.100s (%ld/%ld).",
+      sprintf (buf, "changed uid/gid to %s/%s (%ld/%ld).",
 	       (p && p->pw_name ? p->pw_name : "???"),
                (g && g->gr_name ? g->gr_name : "???"),
 	       (long) uid, (long) gid);
@@ -162,71 +118,28 @@
   else
     {
       char buf [1024];
-      gid_t groups[1024];
-      int n, size;
-
-      if (sgs_errno)
-	{
-	  sprintf (buf, "%s: couldn't setgroups to %.100s (%ld)",
-		   blurb(),
-		   (g && g->gr_name ? g->gr_name : "???"),
-		   (long) gid);
-	  if (sgs_errno == -1)
-	    fprintf(stderr, "%s: unknown error\n", buf);
-	  else
-            {
-              errno = sgs_errno;
-              perror(buf);
-            }
-
-	  fprintf (stderr, "%s: effective group list: ", blurb());
-	  size = sizeof(groups) / sizeof(gid_t);
-          n = getgroups (size - 1, groups);
-          if (n < 0)
-            fprintf (stderr, "unknown!\n");
-          else
-            {
-              int i;
-              fprintf (stderr, "[");
-              for (i = 0; i < n; i++)
-                {
-                  g = getgrgid (groups[i]);
-                  if (i > 0) fprintf (stderr, ", ");
-                  if (g && g->gr_name) fprintf (stderr, "%s", g->gr_name);
-                  else fprintf (stderr, "%ld", (long) groups[i]);
-                }
-              fprintf (stderr, "]\n");
-            }
-        }
-
       if (gid_errno)
 	{
-	  sprintf (buf, "%s: couldn't set gid to %.100s (%ld)",
+	  sprintf (buf, "%s: couldn't set gid to %s (%ld)",
 		   blurb(),
 		   (g && g->gr_name ? g->gr_name : "???"),
 		   (long) gid);
 	  if (gid_errno == -1)
 	    fprintf(stderr, "%s: unknown error\n", buf);
 	  else
-            {
-              errno = gid_errno;
-              perror(buf);
-            }
+	    perror(buf);
 	}
 
       if (uid_errno)
 	{
-	  sprintf (buf, "%s: couldn't set uid to %.100s (%ld)",
+	  sprintf (buf, "%s: couldn't set uid to %s (%ld)",
 		   blurb(),
 		   (p && p->pw_name ? p->pw_name : "???"),
 		   (long) uid);
 	  if (uid_errno == -1)
 	    fprintf(stderr, "%s: unknown error\n", buf);
 	  else
-            {
-              errno = uid_errno;
-              perror(buf);
-            }
+	    perror(buf);
 	}
 
       return -1;
@@ -350,7 +263,7 @@
 	!strcmp (p->pw_name, "games"))
       {
 	static char buf [1024];
-	sprintf (buf, "running as %.100s",
+	sprintf (buf, "running as %s",
 		 (p && p->pw_name && *p->pw_name
 		  ? p->pw_name : "<unknown>"));
 	si->nolock_reason = buf;