Synopsis

Important: kernel security and bug fix update

Type/Severity

Security Advisory: Important

Topic

Updated kernel packages that fix three security issues and several bugs are
now available for Red Hat Enterprise Linux 4.

The Red Hat Security Response Team has rated this update as having
important security impact. Common Vulnerability Scoring System (CVSS) base
scores, which give detailed severity ratings, are available for each
vulnerability from the CVE links in the References section.

Description

The kernel packages contain the Linux kernel, the core of any Linux
operating system.

Security fixes:

• a NULL pointer dereference flaw was found in the Linux kernel NFSv4

implementation. Several of the NFSv4 file locking functions failed to check
whether a file had been opened on the server before performing locking
operations on it. A local, unprivileged user on a system with an NFSv4
share mounted could possibly use this flaw to cause a kernel panic (denial
of service) or escalate their privileges. (CVE-2009-3726, Important)

• a flaw was found in the sctp_process_unk_param() function in the Linux

kernel Stream Control Transmission Protocol (SCTP) implementation. A remote
attacker could send a specially-crafted SCTP packet to an SCTP listening
port on a target system, causing a kernel panic (denial of service).
(CVE-2010-1173, Important)

• a race condition between finding a keyring by name and destroying a freed

keyring was found in the Linux kernel key management facility. A local,
unprivileged user could use this flaw to cause a kernel panic (denial of
service) or escalate their privileges. (CVE-2010-1437, Important)

Red Hat would like to thank Simon Vallet for responsibly reporting
CVE-2009-3726; and Jukka Taimisto and Olli Jarva of Codenomicon Ltd, Nokia
Siemens Networks, and Wind River on behalf of their customer, for
responsibly reporting CVE-2010-1173.

Bug fixes:

• RHBA-2007:0791 introduced a regression in the Journaling Block Device

(JBD). Under certain circumstances, removing a large file (such as 300 MB
or more) did not result in inactive memory being freed, leading to the
system having a large amount of inactive memory. Now, the memory is
correctly freed. (BZ#589155)

• the timer_interrupt() routine did not scale lost real ticks to logical

ticks correctly, possibly causing time drift for 64-bit Red Hat Enterprise
Linux 4 KVM (Kernel-based Virtual Machine) guests that were booted with the
"divider=x" kernel parameter set to a value greater than 1. "warning: many
lost ticks" messages may have been logged on the affected guest systems.
(BZ#590551)

• a bug could have prevented NFSv3 clients from having the most up-to-date

file attributes for files on a given NFSv3 file system. In cases where a
file type changed, such as if a file was removed and replaced with a
directory of the same name, the NFSv3 client may not have noticed this
change until stat(2) was called (for example, by running "ls -l").
(BZ#596372)

• RHBA-2007:0791 introduced bugs in the Linux kernel PCI-X subsystem. These

could have caused a system deadlock on some systems where the BIOS set the
default Maximum Memory Read Byte Count (MMRBC) to 4096, and that also use
the Intel PRO/1000 Linux driver, e1000. Errors such as "e1000: eth[x]:
e1000_clean_tx_irq: Detected Tx Unit Hang" were logged. (BZ#596374)

• an out of memory condition in a KVM guest, using the virtio-net network

driver and also under heavy network stress, could have resulted in
that guest being unable to receive network traffic. Users had to manually
remove and re-add the virtio_net module and restart the network service
before networking worked as expected. Such memory conditions no longer
prevent KVM guests receiving network traffic. (BZ#597310)

• when an SFQ qdisc that limited the queue size to two packets was added to

a network interface, sending traffic through that interface resulted in a
kernel crash. Such a qdisc no longer results in a kernel crash. (BZ#597312)

• when an NFS client opened a file with the O_TRUNC flag set, it received

a valid stateid, but did not use that stateid to perform the SETATTR call.
Such cases were rejected by Red Hat Enterprise Linux 4 NFS servers with an
"NFS4ERR_BAD_STATEID" error, possibly preventing some NFS clients from
writing files to an NFS file system. (BZ#597314)

Users should upgrade to these updated packages, which contain backported
patches to correct these issues. The system must be rebooted for this
update to take effect.

Solution

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

This update is available via the 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

To install kernel packages manually, use "rpm -ivh [package]". Do not
use "rpm -Uvh" as that will remove the running kernel binaries from
your system. You may use "rpm -e" to remove old kernels after
determining that the new kernel functions properly on your system.

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 for x86_64 - Extended Update Support 4.8 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 4.8 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 4.8 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 IBM z Systems - Extended Update Support 4.8 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 4.8 s390
• Red Hat Enterprise Linux for Power, big endian 4 ppc
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 4.8 ppc

Fixes

• BZ - 529227 - CVE-2009-3726 kernel: nfsv4: kernel panic in nfs4_proc_lock()
• BZ - 584645 - CVE-2010-1173 kernel: sctp: crash due to malformed SCTPChunkInit packet
• BZ - 585094 - CVE-2010-1437 kernel: keyrings: find_keyring_by_name() can gain the freed keyring
• BZ - 589155 - jbd not releasing data buffers, causing high inactive meory in RHEL4.6 /proc/meminfo [rhel-4.8.z]
• BZ - 590551 - time drift due to incorrect accounting of lost ticks with VXTIME_PMTMR mode and VXTIME_TSC mode if 'tick_divider' > 1 [rhel-4.8.z]
• BZ - 596372 - NFSv3 file attributes are not updated by READDIRPLUS reply [rhel-4.8.z]
• BZ - 596374 - e1000_clean_tx_irq: Detected Tx Unit Hang [rhel-4.8.z]
• BZ - 597310 - Lost the network in a KVM VM on top of 4.9 [rhel-4.8.z]
• BZ - 597312 - SFQ qdisc crashes with limit of 2 packets [rhel-4.8.z]
• BZ - 597314 - cthon test5 failing on nfsv4 with rhel6 client vs. rhel4 server [rhel-4.8.z]

CVEs

• CVE-2009-3726
• CVE-2010-1173
• CVE-2010-1437

References