RHBA-2009:0991 - Bug Fix Advisory

Topic

An updated autofs package that fixes several bugs is now available.

Description

The autofs utility controls the operation of the automount daemon, which
automatically mounts and unmounts file systems after a period of
inactivity. File systems can include network file systems, CD-ROMs,
diskettes, and other media.

This updated package fixes the following bugs:

• The method that the automount daemon used to parse maps failed when

applied to rootless multi-mount map entries. Therefore, presented with such
entries, autofs would not mount them. Improvements to the parsing code
allow autofs to interpret these entries correctly and mount them. (BZ#452202)

• the multi-map lookup code contained a race that could result in automount

reading two maps in quick succession. Reading the second map invalidated
the cache entries created by the first map, and in some configurations,
this led to failed lookups for valid automount keys. The lookup code now
passes time into the lookup_ghost functions, and therefore avoids
incorrectly clearing the cache. Automount now reliably looks up valid keys.
(BZ#466044)

• the automount daemon used a buffer 128 bytes long to pass information to

SIOCGIFCONF about the addresses on the local machine. Since the details of
each interface are 40 bytes long, the daemon could pass information on no
more than three local interfaces. Autofs would therefore correctly mount
NFS directories that mapped to three local IP addresses, but directories
mapped to any further local IP addresses were treated as if they were on
remote systems. The automount daemon now dynamically allocates a buffer,
ensuring that it is large enough to contain information on all interfaces
on the system. Directories mapped to local IP addresses are now correctly
represented as part of the local system. (BZ#476767)

• a new map type (null) was added to automount, but the man page was not

updated to explain the use of this feature. The man page now
includes an entry that documents the -null directive. (BZ#436060)

• autofs can be configured to convert underscores to dots in NIS map

names. When processing a multi-map entry, autofs performed this conversion
correctly for the first map, but would not make the conversion for any
subsequent maps. This would prevent autofs from using some NIS maps. Autofs
now applies the UNDERSCORETODOT conversion to all maps in a multi-map
entry, and is therefore able to use these maps. (BZ#466040)

• automount uses umount(8) when expiring mounts and umount(8) can wait

indefinitely for a server to respond. This can lead to the expire being
blocked causing mounts not to be expired for a long period of time in the
same /usr/sbin/automount process (that is, the mount that the given
automount process in managing). Consequently, if a server was unreachable,
then automount would not unmount any expired mounts, even on the servers
that are responding. Systems could then be left with a large number of
mounts that can be expired but are not. Automount now includes a command
line option to specify a time for automount to wait before giving up and
moving on to remaining mounts. Expired mounts can therefore be unmounted
even if some servers do not respond. (BZ#453999)

• in a replicated environment, the automount daemon probes a list of remote

hosts for their proximity and NFS version. If hosts fail to respond, they
are removed from the list. If no remote hosts reply at all, the list may
become empty. Previously, the daemon was not able to handle this case and
would cause a segmentation fault (by dereferencing a NULL pointer).
Automount now features improved probing code that returns to looking for
local hosts even if no remote hosts respond. (#465237)

• a logic error in the map parser caused the automount daemon to not

recognize the --no-slashify-colons option. As a result, any maps which
required the preservation of colons would not be parsed properly. This
error has been fixed. (BZ#485516)

Users of autofs should upgrade to this updated package, which resolves
these issues and adds this enhancement.

Solution

Before applying this update, make sure that all previously-released
errata relevant to your system have been applied.

This update is available via Red Hat Network. Details on how to use
the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 4 x86_64
• Red Hat Enterprise Linux Server 4 ia64
• Red Hat Enterprise Linux Server 4 i386
• Red Hat Enterprise Linux Workstation 4 x86_64
• Red Hat Enterprise Linux Workstation 4 ia64
• Red Hat Enterprise Linux Workstation 4 i386
• Red Hat Enterprise Linux Desktop 4 x86_64
• Red Hat Enterprise Linux Desktop 4 i386
• Red Hat Enterprise Linux for IBM z Systems 4 s390x
• Red Hat Enterprise Linux for IBM z Systems 4 s390
• Red Hat Enterprise Linux for Power, big endian 4 ppc

Fixes

• BZ - 436060 - automount null map type not documented in man page
• BZ - 452202 - autofs doesn't parse multi-mount quite right
• BZ - 465237 - [CRM#1837798] automount NULL pointer dereference segmentation fault
• BZ - 466040 - autofs does not apply the UNDERSCORE_TO_DOT conversion to all maps in a multi-map entry
• BZ - 466044 - all maps in a multi-map entry should be cached with the same time
• BZ - 476767 - Autofs doesn't recognize the local host as local when using many interfaces
• BZ - 485516 - autofs does not recognize the [no-]slashify-colon option
• BZ - 489798 - Autofs broken for non-nfs network file systems

CVEs

(none)

References

(none)