10 - RHSA-2010:0606

Problem Description:

Updated kernel packages that fix multiple security issues and one bug are now available for Red Hat Enterprise Linux 4.

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.

2. Relevant releases/architectures:

Red Hat Enterprise Linux AS version 4 - i386, ia64, noarch, ppc, s390, s390x, x86_64 Red Hat Enterprise Linux Desktop version 4 - i386, noarch, x86_64 Red Hat Enterprise Linux ES version 4 - i386, ia64, noarch, x86_64 Red Hat Enterprise Linux WS version 4 - i386, ia64, 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 flaw was found in the CIFSSMBWrite() function in the Linux kernel Common Internet File System (CIFS) implementation. A remote attacker could send a specially-crafted SMB response packet to a target CIFS client, resulting in a kernel panic (denial of service). (CVE-2010-2248, Important)

* buffer overflow flaws were found in the Linux kernel's implementation of the server-side External Data Representation (XDR) for the Network File System (NFS) version 4. An attacker on the local network could send a specially-crafted large compound request to the NFSv4 server, which could possibly result in a kernel panic (denial of service) or, potentially, code execution. (CVE-2010-2521, Important)

This update also fixes the following bug:

* the rpc_call_async() function in the SUN Remote Procedure Call (RPC) subsystem in the Linux kernel had a reference counting bug. In certain situations, some Network Lock Manager (NLM) messages may have triggered this bug on NFSv2 and NFSv3 servers, leading to a kernel panic (with "kernel BUG at fs/lockd/host.c:[xxx]!" logged to "/var/log/messages"). (BZ#612962)

Users should 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 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.

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

608583 - CVE-2010-2248 kernel: cifs: Fix a kernel BUG with remote OS/2 server 612028 - CVE-2010-2521 kernel: nfsd4: bug in read_buf 612962 - [4.4] The kernel BUG occurred with the message 'fs/lockd/host.c:252!' [rhel-4.8.z]