diff -ru schroot-1.1.5/sbuild/sbuild-lock.cc schroot-1.1.5.centos/sbuild/sbuild-lock.cc
--- schroot-1.1.5/sbuild/sbuild-lock.cc	2007-07-08 11:23:29.000000000 +0200
+++ schroot-1.1.5.centos/sbuild/sbuild-lock.cc	2007-09-11 10:33:36.000000000 +0200
@@ -251,7 +251,16 @@
   if (locked)
     {
       pid_t status = 0;
+      uid_t olduid;
+      gid_t oldgid;
+      olduid = getuid();
+      oldgid = getgid();
+      setuid(0);
+      setgid(0);
       status = dev_unlock(this->device.c_str(), getpid());
+      setreuid(olduid,0);
+      setregid(oldgid,0);
+
       if (status < 0) // Failure
 	log_exception_warning(error(DEVICE_UNLOCK));
     }
@@ -265,7 +274,13 @@
     {
       lock_timeout = false;
 
+      uid_t olduid;
+      gid_t oldgid;
       struct itimerval timeout_timer;
+
+      olduid = getuid();
+      oldgid = getgid();
+
       timeout_timer.it_interval.tv_sec = timeout_timer.it_interval.tv_usec = 0;
       timeout_timer.it_value.tv_sec = timeout;
       timeout_timer.it_value.tv_usec = 0;
@@ -282,7 +297,11 @@
 	{
 	  if (lock_type == LOCK_SHARED || lock_type == LOCK_EXCLUSIVE)
 	    {
+	      setuid(0);
+	      setgid(0);
 	      status = dev_lock(this->device.c_str());
+	      setreuid(olduid,0);
+	      setregid(oldgid,0);
 	      if (status == 0) // Success
 		{
 		  this->locked = true;
@@ -295,7 +314,13 @@
 	    }
 	  else
 	    {
-	      pid_t cur_lock_pid = dev_testlock(this->device.c_str());
+	      pid_t cur_lock_pid;
+	      setuid(0);
+	      setgid(0);
+	      cur_lock_pid = dev_testlock(this->device.c_str());
+	      setreuid(olduid,0);
+	      setregid(oldgid,0);
+
 	      if (cur_lock_pid < 0) // Test failure
 		{
 		  throw error(DEVICE_TEST);
@@ -306,7 +331,11 @@
 		  // "drop" our nonexistent lock.
 		  break;
 		}
+	      setuid(0);
+	      setgid(0);
 	      status = dev_unlock(this->device.c_str(), getpid());
+	      setreuid(olduid,0);
+	      setregid(oldgid,0);
 	      if (status == 0) // Success
 		{
 		  this->locked = false;