6.2 - RHSA-2013:1292

Problem Description:

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

The Red Hat Security Response Team has rated this update as having moderate 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.

2. Relevant releases/architectures:

Red Hat Enterprise Linux (v. 5 server) - i386, ia64, noarch, ppc, s390x, x86_64 Red Hat Enterprise Linux Desktop (v. 5 client) - i386, noarch, x86_64

3. Description:

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

This update fixes the following security issues:

* A use-after-free flaw was found in the madvise() system call implementation in the Linux kernel. A local, unprivileged user could use this flaw to cause a denial of service or, potentially, escalate their privileges. (CVE-2012-3511, Moderate)

* A flaw was found in the way the Linux kernel's TCP/IP protocol suite implementation handled IPv6 sockets that used the UDP_CORK option. A local, unprivileged user could use this flaw to cause a denial of service. (CVE-2013-4162, Moderate)

* An information leak flaw in the Linux kernel could allow a local, unprivileged user to leak kernel memory to user-space. (CVE-2013-2141, Low)

Red Hat would like to thank Hannes Frederic Sowa for reporting CVE-2013-4162.

This update also fixes the following bugs:

* A bug in the be2net driver prevented communication between NICs using be2net. This update applies a patch addressing this problem along with several other upstream patches that fix various other problems. Traffic between NICs using the be2net driver now proceeds as expected. (BZ#983864)

* A recent patch fixing a problem that prevented communication between NICs using the be2net driver caused the firmware of NICs to become unresponsive, and thus triggered a kernel panic. The problem was caused by unnecessary usage of a hardware workaround that allows skipping VLAN tag insertion. A patch has been applied and the workaround is now used only when the multi-channel configuration is enabled on the NIC. Note that the bug only affected the NICs with firmware version 4.2.xxxx. (BZ#999819)

* A bug in the autofs4 mount expiration code could cause the autofs4 module to falsely report a busy tree of NFS mounts as "not in use". Consequently, automount attempted to unmount the tree and failed with a "failed to umount offset" error, leaving the mount tree to appear as empty directories. A patch has been applied to remove an incorrectly used autofs dentry mount check and the aforementioned problem no longer occurs. (BZ#1001488)

* A race condition in the be_open function in the be2net driver could trigger the BUG_ON() macro, which resulted in a kernel panic. A patch addressing this problem has been applied and the race condition is now avoided by enabling polling before enabling interrupts globally. The kernel no longer panics in this situation. (BZ#1005239)

All kernel users are advised to upgrade to these updated packages, which contain backported patches to correct these issues. The system must be rebooted for this update to take effect.

4. 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/site/articles/11258

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.

5. Bugs fixed (http://bugzilla.redhat.com/):

849734 - CVE-2012-3511 kernel: mm: use-after-free in madvise_remove() 970873 - CVE-2013-2141 Kernel: signal: information leak in tkill/tgkill 987627 - CVE-2013-4162 Kernel: net: panic while pushing pending data out of a IPv6 socket with UDP_CORK enabled