From: Flávio Leitner <fleitner@redhat.com>
Subject: mount should set proper permissions on locktime

When creating the "/etc/mtab~" lockfile (specifically 'linktargetfile'  in the
lock_mtab function), the file is created with incorrect permissions ('000')
which necessitates root to leverage CAP_DAC_OVERRIDE. If proper file modes (it
would appear 0600 would be sufficient) were used in the open this would
function properly with CAP_DAC_OVERRIDE revoked.

--- util-linux-2.12a/mount/fstab.c.kzak	2007-07-31 12:13:26.000000000 +0200
+++ util-linux-2.12a/mount/fstab.c	2007-07-31 12:13:11.000000000 +0200
@@ -433,7 +433,7 @@
 	linktargetfile = xmalloc(strlen(MOUNTLOCK_LINKTARGET) + 20);
 	sprintf(linktargetfile, MOUNTLOCK_LINKTARGET, getpid ());
 
-	i = open (linktargetfile, O_WRONLY|O_CREAT, 0);
+	i = open (linktargetfile, O_WRONLY|O_CREAT, S_IRUSR|S_IWUSR);
 	if (i < 0) {
 		int errsv = errno;
 		/* linktargetfile does not exist (as a file)