(RHSA-2011:1691) Low: util-linux-ng security, bug fix, and enhancement update

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 (mounted file systems table) 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. (CVE-2011-1675,
CVE-2011-1677)

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. (BZ#675999)

• 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. (BZ#679741)

• 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.
  (BZ#684203)

• 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.
  (BZ#696959)

• When providing information on interprocess communication (IPC)
  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. (BZ#712158)

• 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.
  (BZ#712808)

• 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. (BZ#716995)

• 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. (BZ#723352)

• The previous version of the tailf(1) 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. (BZ#679831)

• The fstab(5) manual page has been updated to clarify that empty lines in
  the /etc/fstab configuration file are ignored. (BZ#694648)

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.
  (BZ#692119)

• The login utility has been updated to provide support for failed login
  attempts that are reported by PAM. (BZ#696731)

• The lsblk utility has been updated to provide additional information
  about the topology and status of block devices. (BZ#723638)

• The agetty utility has been updated to pass the hostname to the login
  utility. (BZ#726092)

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.