RHSA-2013:1450 - Security Advisory

Topic

Updated kernel packages that fix three security issues and several bugs are
now available for Red Hat Enterprise Linux 6.3 Extended Update Support.

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.

• It was found that the fix for CVE-2012-3552 released via RHSA-2012:1540

introduced an invalid free flaw in the Linux kernel's TCP/IP protocol suite
implementation. A local, unprivileged user could use this flaw to corrupt
kernel memory via crafted sendmsg() calls, allowing them to cause a denial
of service or, potentially, escalate their privileges on the
system. (CVE-2013-2224, Important)

• An information leak flaw was found in the way Linux kernel's device

mapper subsystem, under certain conditions, interpreted data written to
snapshot block devices. An attacker could use this flaw to read data from
disk blocks in free space, which are normally inaccessible. (CVE-2013-4299,
Moderate)

• A format string flaw was found in the b43_do_request_fw() function in the

Linux kernel's b43 driver implementation. A local user who is able to
specify the "fwpostfix" b43 module parameter could use this flaw to cause a
denial of service or, potentially, escalate their privileges.
(CVE-2013-2852, Low)

Red Hat would like to thank Fujitsu for reporting CVE-2013-4299, and Kees
Cook for reporting CVE-2013-2852.

This update also fixes the following bugs:

• An insufficiently designed calculation in the CPU accelerator could cause

an arithmetic overflow in the set_cyc2ns_scale() function if the system
uptime exceeded 208 days prior to using kexec to boot into a new
kernel. This overflow led to a kernel panic on the systems using the Time
Stamp Counter (TSC) clock source, primarily the systems using Intel Xeon E5
processors that do not reset TSC on soft power cycles. A patch has been
applied to modify the calculation so that this arithmetic overflow and
kernel panic can no longer occur under these circumstances. (BZ#1004185)

• A race condition in the abort task and SPP device task management path of

the isci driver could, under certain circumstances, cause the driver to
fail cleaning up timed-out I/O requests that were pending on an SAS disk
device. As a consequence, the kernel removed such a device from the
system. A patch applied to the isci driver fixes this problem by sending
the task management function request to the SAS drive anytime the abort
function is entered and the task has not completed. The driver now cleans
up timed-out I/O requests as expected in this situation. (BZ#1007467)

• A kernel panic could occur during path failover on systems using multiple

iSCSI, FC or SRP paths to connect an iSCSI initiator and an iSCSI
target. This happened because a race condition in the SCSI driver allowed
removing a SCSI device from the system before processing its run queue,
which led to a NULL pointer dereference. The SCSI driver has been modified
and the race is now avoided by holding a reference to a SCSI device run
queue while it is active. (BZ#1008507)

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.

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.

Affected Products

• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.3 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.3 i386
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.3 s390x
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.3 ppc64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.3 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.3 i386
• Red Hat Enterprise Linux EUS Compute Node 6.3 x86_64

Fixes

• BZ - 969518 - CVE-2013-2852 kernel: b43: format string leaking into error msgs
• BZ - 979936 - CVE-2013-2224 kernel: net: IP_REPOPTS invalid free
• BZ - 1004233 - CVE-2013-4299 kernel: dm: dm-snapshot data leak

CVEs

• CVE-2013-2852
• CVE-2013-2224
• CVE-2013-4299

References

• https://access.redhat.com/security/updates/classification/#important