The util-linux-ng packages contain a large variety of low-level system utilities that are necessary for a Linux operating system to function. Multiple flaws were found in the way the mount and umount commands performed mtab file updates. A local, unprivileged user allowed to mount or unmount file systems could use these flaws to corrupt the mtab file and create a stale lock file, preventing other users from mounting and unmounting file systems. This update also fixes the following bugs: * Due to a hard coded limit of 128 devices, an attempt to run the "blkid -c" command on more than 128 devices caused blkid to terminate unexpectedly. This update increases the maximum number of devices to 8192 so that blkid no longer crashes in this scenario. * Previously, the "swapon -a" command did not detect device-mapper devices that were already in use. This update corrects the swapon utility to detect such devices as expected. * Prior to this update, the presence of an invalid line in the /etc/fstab file could cause the umount utility to terminate unexpectedly with a segmentation fault. This update applies a patch that corrects this error so that umount now correctly reports invalid lines and no longer crashes. * Previously, an attempt to use the wipefs utility on a partitioned device caused the utility to terminate unexpectedly with an error. This update adapts wipefs to only display a warning message in this situation. * When providing information on interprocess communication facilities, the ipcs utility could previously display a process owner as a negative number if the user"s UID was too large. This update adapts the underlying source code to make sure the UID values are now displayed correctly. * In the installation scriptlets, the uuidd package uses the chkconfig utility to enable and disable the uuidd service. Previously, this package did not depend on the chkconfig package, which could lead to errors during installation if chkconfig was not installed. This update adds chkconfig to the list of dependencies so that such errors no longer occur. * The previous version of the /etc/udev/rules.d/60-raw.rules file contained a statement that both this file and raw devices are deprecated. This is no longer true and the Red Hat Enterprise Linux kernel supports this functionality. With this update, the aforementioned file no longer contains this incorrect statement. * Previously, an attempt to use the cfdisk utility to read the default Red Hat Enterprise Linux 6 partition layout failed with an error. This update corrects this error and the cfdisk utility can now read the default partition layout as expected. * The previous version of the tailf manual page incorrectly stated that users can use the "--lines=NUMBER" command line option to limit the number of displayed lines. However, the tailf utility does not allow the use of the equals sign between the option and its argument. This update corrects this error. * The fstab manual page has been updated to clarify that empty lines in the /etc/fstab configuration file are ignored. As well, this update adds the following enhancements: * A new fstrim utility has been added to the package. This utility allows the root user to discard unused blocks on a mounted file system. * The login utility has been updated to provide support for failed login attempts that are reported by PAM. * The lsblk utility has been updated to provide additional information about the topology and status of block devices. * The agetty utility has been updated to pass the hostname to the login utility. All users of util-linux-ng are advised to upgrade to these updated packages, which contain backported patches to correct these issues and add these enhancements.