Topic

Updated kernel packages that fix several security issues, various bugs, and
add an enhancement are now available for Red Hat Enterprise Linux 6.

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:

• An integer overflow flaw in ib_uverbs_poll_cq() could allow a local,

unprivileged user to cause a denial of service or escalate their
privileges. (CVE-2010-4649, Important)

• An integer signedness flaw in drm_modeset_ctl() could allow a local,

unprivileged user to cause a denial of service or escalate their
privileges. (CVE-2011-1013, Important)

• The Radeon GPU drivers in the Linux kernel were missing sanity checks for

the Anti Aliasing (AA) resolve register values which could allow a local,
unprivileged user to cause a denial of service or escalate their privileges
on systems using a graphics card from the ATI Radeon R300, R400, or R500
family of cards. (CVE-2011-1016, Important)

• A flaw in dccp_rcv_state_process() could allow a remote attacker to

cause a denial of service, even when the socket was already closed.
(CVE-2011-1093, Important)

• A flaw in the Linux kernel's Stream Control Transmission Protocol (SCTP)

implementation could allow a remote attacker to cause a denial of service
if the sysctl "net.sctp.addip_enable" and "auth_enable" variables were
turned on (they are off by default). (CVE-2011-1573, Important)

• A memory leak in the inotify_init() system call. In some cases, it could

leak a group, which could allow a local, unprivileged user to eventually
cause a denial of service. (CVE-2010-4250, Moderate)

• A missing validation of a null-terminated string data structure element

in bnep_sock_ioctl() could allow a local user to cause an information leak
or a denial of service. (CVE-2011-1079, Moderate)

• An information leak in bcm_connect() in the Controller Area Network (CAN)

Broadcast Manager implementation could allow a local, unprivileged user to
leak kernel mode addresses in "/proc/net/can-bcm". (CVE-2010-4565, Low)

• A flaw was found in the Linux kernel's Integrity Measurement Architecture

(IMA) implementation. When SELinux was disabled, adding an IMA rule which
was supposed to be processed by SELinux would cause ima_match_rules() to
always succeed, ignoring any remaining rules. (CVE-2011-0006, Low)

• A missing initialization flaw in the XFS file system implementation could

lead to an information leak. (CVE-2011-0711, Low)

• Buffer overflow flaws in snd_usb_caiaq_audio_init() and

snd_usb_caiaq_midi_init() could allow a local, unprivileged user with
access to a Native Instruments USB audio device to cause a denial of
service or escalate their privileges. (CVE-2011-0712, Low)

• The start_code and end_code values in "/proc/[pid]/stat" were not

protected. In certain scenarios, this flaw could be used to defeat Address
Space Layout Randomization (ASLR). (CVE-2011-0726, Low)

• A flaw in dev_load() could allow a local user who has the CAP_NET_ADMIN

capability to load arbitrary modules from "/lib/modules/", instead of only
netdev modules. (CVE-2011-1019, Low)

• A flaw in ib_uverbs_poll_cq() could allow a local, unprivileged user to

cause an information leak. (CVE-2011-1044, Low)

• A missing validation of a null-terminated string data structure element

in do_replace() could allow a local user who has the CAP_NET_ADMIN
capability to cause an information leak. (CVE-2011-1080, Low)

Red Hat would like to thank Vegard Nossum for reporting CVE-2010-4250;
Vasiliy Kulikov for reporting CVE-2011-1079, CVE-2011-1019, and
CVE-2011-1080; Dan Rosenberg for reporting CVE-2010-4565 and CVE-2011-0711;
Rafael Dominguez Vega for reporting CVE-2011-0712; and Kees Cook for
reporting CVE-2011-0726.

This update also fixes various bugs and adds an 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 resolve 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 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 656830 - CVE-2010-4250 kernel: inotify memory leak
• BZ - 664544 - CVE-2010-4565 kernel: CAN info leak
• BZ - 667912 - CVE-2011-0006 kernel: ima: fix add LSM rule bug
• BZ - 667916 - CVE-2010-4649 CVE-2011-1044 kernel: IB/uverbs: Handle large number of entries in poll CQ
• BZ - 670850 - [6.0] System reset when changing EFI variable on large memory system [rhel-6.0.z]
• BZ - 677260 - CVE-2011-0711 kernel: xfs: prevent leaking uninitialized stack memory in FSGEOMETRY_V1
• BZ - 677881 - CVE-2011-0712 kernel: ALSA: caiaq - Fix possible string-buffer overflow
• BZ - 679925 - CVE-2011-1013 kernel: drm_modeset_ctl signedness issue
• BZ - 680000 - CVE-2011-1016 kernel: drm/radeon/kms: check AA resolve registers on r300
• BZ - 680360 - CVE-2011-1019 kernel: CAP_SYS_MODULE bypass via CAP_NET_ADMIN
• BZ - 681260 - CVE-2011-1079 kernel: bnep device field missing NULL terminator
• BZ - 681262 - CVE-2011-1080 kernel: ebtables stack infoleak
• BZ - 682954 - CVE-2011-1093 kernel: dccp: fix oops on Reset after close
• BZ - 683810 - [6.1] Common code infrastructure for VLAN null tagging [rhel-6.0.z]
• BZ - 684275 - kernel: BUG: warning at drivers/char/tty_audit.c:55/tty_audit_buf_free() [rhel-6.0.z]
• BZ - 684569 - CVE-2011-0726 kernel: proc: protect mm start_code/end_code in /proc/pid/stat
• BZ - 691777 - Bonded and vlan tagged network does not work in KVM guest [rhel-6.0.z]
• BZ - 694073 - 82576 stuck after PCI AER error [rhel-6.0.z]
• BZ - 694186 - kswapd0 100% [rhel-6.0.z]
• BZ - 695383 - CVE-2011-1573 kernel: sctp: fix to calc the INIT/INIT-ACK chunk length correctly to set
• BZ - 696889 - emc_clariion error handler panics with multiple failures [rhel-6.0.z]
• BZ - 698109 - Bond interface flapping and increasing rx_missed_errors [rhel-6.0.z]

CVEs

• CVE-2010-4649
• CVE-2010-4565
• CVE-2010-4250
• CVE-2011-1044
• CVE-2011-1080
• CVE-2011-0726
• CVE-2011-1019
• CVE-2011-1093
• CVE-2011-1079
• CVE-2011-1013
• CVE-2011-0711
• CVE-2011-0006
• CVE-2011-1573
• CVE-2011-1016
• CVE-2011-0712

References

• https://access.redhat.com/security/updates/classification/#important
• http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Technical_Notes/ape.html#RHSA-2011-0498