RHSA-2010:0424 - Security Advisory

Topic

Updated kernel packages that fix one security issue and add one enhancement
are now available for Red Hat Enterprise Linux 4.7 Extended Update Support.

The Red Hat Security Response Team has rated this update as having
important security impact. A Common Vulnerability Scoring System (CVSS)
base score, which gives a detailed severity rating, is available from the
CVE link 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 issue:

• a use-after-free flaw was found in the tcp_rcv_state_process() function

in the Linux kernel TCP/IP protocol suite implementation. If a system using
IPv6 had the IPV6_RECVPKTINFO option set on a listening socket, a remote
attacker could send an IPv6 packet to that system, causing a kernel panic
(denial of service). (CVE-2010-1188, Important)

This update also adds the following enhancement:

• kernel support for the iptables connlimit module. This module can be used

to help mitigate some types of denial of service attacks. Note: This update
alone does not address connlimit support. A future iptables package update
will allow connlimit to work correctly. (BZ#563222)

Users should upgrade to these updated packages, which contain backported
patches to correct this issue and add this enhancement. 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 for x86_64 - Extended Update Support 4.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 4.7 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 4.7 i386
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 4.7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 4.7 s390
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 4.7 ppc

Fixes

• BZ - 563222 - [RFE ] Connlimit kernel module support [rhel-4.9] [rhel-4.7.z]
• BZ - 577711 - CVE-2010-1188 kernel: ipv6: skb is unexpectedly freed

CVEs

• CVE-2010-1188

References

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