RHSA-2011:1479 - Security Advisory

Topic

Updated kernel packages that fix multiple security issues, several bugs,
and add one enhancement are now available for Red Hat Enterprise Linux 5.

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.

This update fixes the following security issues:

• Using PCI passthrough without interrupt remapping support allowed Xen

hypervisor guests to generate MSI interrupts and thus potentially inject
traps. A privileged guest user could use this flaw to crash the host or
possibly escalate their privileges on the host. The fix for this issue can
prevent PCI passthrough working and guests starting. Refer to Red Hat
Bugzilla bug 715555 for details. (CVE-2011-1898, Important)

• A flaw was found in the way CIFS (Common Internet File System) shares

with DFS referrals at their root were handled. An attacker on the local
network who is able to deploy a malicious CIFS server could create a CIFS
network share that, when mounted, would cause the client system to crash.
(CVE-2011-3363, Moderate)

• A NULL pointer dereference flaw was found in the way the Linux kernel's

key management facility handled user-defined key types. A local,
unprivileged user could use the keyctl utility to cause a denial of
service. (CVE-2011-4110, Moderate)

• A flaw in the way memory containing security-related data was handled in

tpm_read() could allow a local, unprivileged user to read the results of a
previously run TPM command. (CVE-2011-1162, Low)

• A NULL pointer dereference flaw was found in the Linux kernel's HFS file

system implementation. A local attacker could use this flaw to cause a
denial of service by mounting a disk that contains a specially-crafted HFS
file system with a corrupted MDB extent record. (CVE-2011-2203, Low)

• The I/O statistics from the taskstats subsystem could be read without

any restrictions. A local, unprivileged user could use this flaw to gather
confidential information, such as the length of a password used in a
process. (CVE-2011-2494, Low)

Red Hat would like to thank Yogesh Sharma for reporting CVE-2011-3363;
Peter Huewe for reporting CVE-2011-1162; Clement Lecigne for reporting
CVE-2011-2203; and Vasiliy Kulikov of Openwall for reporting CVE-2011-2494.

This update also fixes several bugs and adds one enhancement. Documentation
for these changes will be available shortly from the Technical Notes
document linked to in the References section.

Users should upgrade to these updated packages, which contain backported
patches to correct these issues, and fix the bugs and add the enhancement
noted in the Technical Notes. 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
https://access.redhat.com/kb/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 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 712774 - CVE-2011-2203 kernel: hfs_find_init() sb->ext_tree NULL pointer dereference
• BZ - 715555 - CVE-2011-1898 virt: VT-d (PCI passthrough) MSI trap injection
• BZ - 716842 - CVE-2011-2494 kernel: taskstats io infoleak
• BZ - 732629 - CVE-2011-1162 kernel: tpm: infoleak
• BZ - 738291 - CVE-2011-3363 kernel: cifs: always do is_path_accessible check in cifs_mount
• BZ - 741273 - Non-responsive scsi target leads to excessive scsi recovery and dm-mp failover time [rhel-5.7.z]
• BZ - 745726 - Host crash when pass-through fails [rhel-5.7.z]
• BZ - 751297 - CVE-2011-4110 kernel: keys: NULL pointer deref in the user-defined key type

CVEs

• CVE-2011-1898
• CVE-2011-3363
• CVE-2011-2494
• CVE-2011-1162
• CVE-2011-2203
• CVE-2011-4110

References

• https://access.redhat.com/security/updates/classification/#important
• https://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html/5.7_Technical_Notes/kernel.html#RHSA-2011-1479
• https://bugzilla.redhat.com/show_bug.cgi?id=715555