RHSA-2009:0955 - Security Advisory

Topic

An updated nfs-utils package that fixes a security issue and multiple bugs
is now available for Red Hat Enterprise Linux 4.

This update has been rated as having moderate security impact by the Red
Hat Security Response Team.

Description

The nfs-utils package provides a daemon for the kernel NFS server and
related tools, which provides a much higher level of performance than the
traditional Linux NFS server used by most users.

A flaw was found in the nfs-utils package provided by RHBA-2008:0742. The
nfs-utils package was missing TCP wrappers support, which could result in
an administrator believing they had access restrictions enabled when they
did not. (CVE-2008-1376)

This update also includes the following bug fixes:

• the "nfsstat" command now displays correct statistics. In previous

versions, performing more than 2^31 RPC calls could cause the "nfsstat"
command to incorrectly display the number of calls as "negative". This was
because "nfsstat" printed statistics from /proc/net/rpc/* files as signed
integers; with this version of nfs-utils, "nfsstat" now reads and prints
these statistics as unsigned integers. (BZ#404831)

• imapd upcalls now support zero-length reads and perform extra bounds

checking in gssd and svcgssd. This fixes a bug in previous versions that
could cause the rpc.imapd daemon to hang when communicating with the
kernel, which would halt any ID translation services. (BZ#448710)

• tcp_wrappers supported in nfs-utils now allows proper application of

hosts access rules defined in /etc/hosts.allow and /etc/hosts.deny. (BZ#494585)

• the nfs init script did not check whether SECURE_NFS was set to "yes"

before starting, stopping, or querying rpc.svcgssd. On systems where
SECURE_NFS was not set to "yes", the nfs init script could not start the
rpc.svcgssd daemon at the "service nfs start" command because the rpcsvcssd
init script would check the status of SECURE_NFS before starting the
daemon. However, at the "service nfs stop" or "service nfs restart"
commands, nfs init script would attempt to stop rpc.svcgssd and then report
a failure because the daemon was not running in the first place. These
error messages may have misled end-users into believing that there was a
genuine problem with their NFS configuration. This version of nfs-utils
contains a fix backported from Red Hat Enterprise Linux 5. nfs-utils now
checks the status of SECURE_NFS before the nfs init script attempts to
start, query or stop rpc.svcgssd and therefore, the irrelevant error
messages seen previously will not appear. (BZ#470423)

• the nfs init script is now fully compliant with Linux Standard Base Core

specifications. This update fixes a bug that prevented "/etc/init.d/nfs
start" from exiting properly if NFS was already running. (BZ#474570)

• /var/lib/nfs/statd/sm is now created with the proper user and group

whenever rpc.statd is called. In previous versions, some thread stack
conditions could incorrectly prevent rpc.statd from creating the
/var/lib/nfs/statd/sm file, which could cause "service nfslock start" to
fail. (BZ#479376)

All users of nfs-utils should upgrade to this updated package, which
resolves these issues.

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 - 404831 - "nfsstat -s" shows negative value
• BZ - 440114 - CVE-2008-1376 nfs-utils: missing tcp_wrappers support
• BZ - 461043 - lockd not using settings in sysconfig/nfs
• BZ - 474570 - Incorrect exit codes from nfs init script
• BZ - 479376 - statd fails to create SM_DIR
• BZ - 494585 - libwrap - Nor ip, nor hostname work,, only when used ALL expression in hosts.deny access is denied

CVEs

• CVE-2008-1376

References

• http://www.redhat.com/security/updates/classification/#moderate