RHSA-2011:1189 - Security Advisory

Topic

Updated kernel packages that fix several security issues, various bugs, and
add two enhancements 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

Security issues:

• Using PCI passthrough without interrupt remapping support allowed KVM

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)

• Flaw in the client-side NLM implementation could allow a local,

unprivileged user to cause a denial of service. (CVE-2011-2491, Important)

• Integer underflow in the Bluetooth implementation could allow a remote

attacker to cause a denial of service or escalate their privileges by
sending a specially-crafted request to a target system via Bluetooth.
(CVE-2011-2497, Important)

• Buffer overflows in the netlink-based wireless configuration interface

implementation could allow a local user, who has the CAP_NET_ADMIN
capability, to cause a denial of service or escalate their privileges on
systems that have an active wireless interface. (CVE-2011-2517, Important)

• Flaw in the way the maximum file offset was handled for ext4 file systems

could allow a local, unprivileged user to cause a denial of service.
(CVE-2011-2695, Important)

• Flaw allowed napi_reuse_skb() to be called on VLAN packets. An attacker

on the local network could use this flaw to send crafted packets to a
target, possibly causing a denial of service. (CVE-2011-1576, Moderate)

• Integer signedness error in next_pidmap() could allow a local,

unprivileged user to cause a denial of service. (CVE-2011-1593, Moderate)

• Race condition in the memory merging support (KSM) could allow a local,

unprivileged user to cause a denial of service. KSM is off by default, but
on systems running VDSM, or on KVM hosts, it is likely turned on by the
ksm/ksmtuned services. (CVE-2011-2183, Moderate)

• Flaw in inet_diag_bc_audit() could allow a local, unprivileged user to

cause a denial of service. (CVE-2011-2213, Moderate)

• Flaw in the way space was allocated in the Global File System 2 (GFS2)

implementation. If the file system was almost full, and a local,
unprivileged user made an fallocate() request, it could result in a denial
of service. Setting quotas to prevent users from using all available disk
space would prevent exploitation of this flaw. (CVE-2011-2689, Moderate)

• Local, unprivileged users could send signals via the sigqueueinfo system

call, with si_code set to SI_TKILL and with spoofed process and user IDs,
to other processes. This flaw does not allow existing permission checks to
be bypassed; signals can only be sent if your privileges allow you to
already do so. (CVE-2011-1182, Low)

• Heap overflow in the EFI GUID Partition Table (GPT) implementation could

allow a local attacker to cause a denial of service by mounting a disk
containing crafted partition tables. (CVE-2011-1776, Low)

• Structure padding in two structures in the Bluetooth implementation was

not initialized properly before being copied to user-space, possibly
allowing local, unprivileged users to leak kernel stack memory to
user-space. (CVE-2011-2492, Low)

• /proc/[PID]/io is world-readable by default. Previously, these files

could be read without any further restrictions. A local, unprivileged user
could read these files, belonging to other, possibly privileged processes
to gather confidential information, such as the length of a password used
in a process. (CVE-2011-2495, Low)

Red Hat would like to thank Vasily Averin for reporting CVE-2011-2491; Dan
Rosenberg for reporting CVE-2011-2497 and CVE-2011-2213; Ryan Sweat for
reporting CVE-2011-1576; Robert Swiecki for reporting CVE-2011-1593; Andrea
Righi for reporting CVE-2011-2183; Julien Tinnes of the Google Security
Team for reporting CVE-2011-1182; Timo Warns for reporting CVE-2011-1776;
Marek Kroemeke and Filip Palian for reporting CVE-2011-2492; and Vasiliy
Kulikov of Openwall for reporting CVE-2011-2495.

Solution

Refer to the Technical Notes, available shortly from the link in the
References, for bug fix and enhancement details.

Users should upgrade to these updated packages, which contain
backported patches to correct these issues, and fix the bugs and add
the enhancements noted in the Technical Notes. The system must be
rebooted for this update to take effect.

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 for x86_64 - Extended Update Support 6.1 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.1 i386
• 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 IBM z Systems - Extended Update Support 6.1 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.1 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
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.1 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.1 i386
• Red Hat Virtual Storage Appliance (from RHUI) 6.1 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems) 6 s390x

Fixes

• BZ - 690028 - CVE-2011-1182 kernel signal spoofing issue
• BZ - 695173 - CVE-2011-1576 kernel: net: Fix memory leak/corruption on VLAN GRO_DROP
• BZ - 697822 - CVE-2011-1593 kernel: proc: signedness issue in next_pidmap()
• BZ - 703019 - CVE-2011-2492 kernel: bluetooth: l2cap and rfcomm: fix 1 byte infoleak to userspace
• BZ - 703026 - CVE-2011-1776 kernel: validate size of EFI GUID partition entries
• BZ - 709393 - CVE-2011-2491 kernel: rpc task leak after flock()ing NFS share
• BZ - 710338 - CVE-2011-2183 kernel: ksm: race between ksmd and exiting task
• BZ - 713827 - Parallel port issue in RHEL 6.0 server
• BZ - 714536 - CVE-2011-2213 kernel: inet_diag: insufficient validation
• BZ - 714982 - GFS2: Update to rhel6.1 broke dovecot writing to a gfs2 filesystem
• BZ - 715555 - CVE-2011-1898 virt: VT-d (PCI passthrough) MSI trap injection
• BZ - 716539 - bump domain memory limits [6.1.z]
• BZ - 716805 - CVE-2011-2497 kernel: bluetooth: buffer overflow in l2cap config request
• BZ - 716825 - CVE-2011-2495 kernel: /proc/PID/io infoleak
• BZ - 718152 - CVE-2011-2517 kernel: nl80211: missing check for valid SSID size in scan operations
• BZ - 720861 - CVE-2011-2689 kernel: gfs2: make sure fallocate bytes is a multiple of blksize
• BZ - 722557 - CVE-2011-2695 kernel: ext4: kernel panic when writing data to the last block of sparse file

CVEs

• CVE-2011-1182
• CVE-2011-1776
• CVE-2011-2492
• CVE-2011-1576
• CVE-2011-2213
• CVE-2011-1593
• CVE-2011-2689
• CVE-2011-2695
• CVE-2011-2517
• CVE-2011-2497
• CVE-2011-2495
• CVE-2011-2491
• CVE-2011-1898
• CVE-2011-2183

References

• https://access.redhat.com/security/updates/classification/#important
• https://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/6.1_Technical_Notes/kernel.html#RHSA-2011-1189
• https://bugzilla.redhat.com/show_bug.cgi?id=715555