Merge lp:~bratsche/xsplash/setgid into lp:xsplash

[Cody Russell]

[Ted Gould (ted)]

review: Approve

[Ted Gould (ted)]

From the patch attached to bug 439272:

Description: setuid()'s return must be checked in the case that some RLIMIT
 or other issue does not stop the transition. Additionally, setresuid()
 should be used so that the process cannot regain its prior uid.

review: Needs Fixing

[lp:~bratsche/xsplash/setgid]

82. By Cody Russell on 2009-10-04

use setresuid/setresgid

[Cody Russell (bratsche)]

> From the patch attached to bug 439272:
>
> Description: setuid()'s return must be checked in the case that some RLIMIT
> or other issue does not stop the transition. Additionally, setresuid()
> should be used so that the process cannot regain its prior uid.

Okay, pushed a new revision that switches to setresuid/setresgid.

[Ted Gould (ted)]

review: Approve

=== modified file 'src/xsplash.c'
--- src/xsplash.c	2009-10-01 20:56:55 +0000
+++ src/xsplash.c	2009-10-04 00:15:21 +0000
@@ -17,10 +17,12 @@
  *    Cody Russell <[e-mail]>
  */
 
+#define _GNU_SOURCE
+#include <unistd.h>
+
 #include <stdlib.h>
 #include <math.h>
 #include <string.h>
-#include <unistd.h>
 #include <pwd.h>
 #include <dirent.h>
 
@@ -913,14 +915,13 @@
 int
 main (int argc, char *argv[])
 {
-  XsplashServer *server;
-  GError *error = NULL;
-  GOptionContext *context;
+  XsplashServer   *server;
+  GError          *error = NULL;
+  GOptionContext  *context;
   DBusGConnection *system_bus;
   DBusGProxy      *bus_proxy;
   guint            nameret = 0;
-  struct passwd *pwd;
-  uid_t uid;
+  struct passwd   *pwd;
 
   pwd = getpwnam (XSPLASH_USER);
   if (pwd == NULL)
@@ -929,9 +930,17 @@
       return 1;
     }
 
-  uid = pwd->pw_uid;
+  if (setresgid (pwd->pw_gid, pwd->pw_gid, pwd->pw_gid))
+    {
+      g_error ("Failed to setresgid to `%s'", XSPLASH_USER);
+      return 1;
+    }
 
-  setuid (uid);
+  if (setresuid (pwd->pw_uid, pwd->pw_uid, pwd->pw_uid))
+    {
+      g_error ("Failed to setresuid to `%s'", XSPLASH_USER);
+      return 1;
+    }
 
   context = g_option_context_new ("xsplash");
   g_option_context_add_main_entries (context,