RHSA-2014:0433 - Security Advisory

Topic

Updated kernel packages that fix two security issues, three bugs, and add
one enhancement 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.

Description

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

• A flaw was found in the way the Linux kernel's TCP/IP protocol suite

implementation handled TCP packets with both the SYN and FIN flags set.
A remote attacker could use this flaw to consume an excessive amount of
resources on the target system, potentially resulting in a denial of
service. (CVE-2012-6638, Moderate)

• A flaw was found in the way the Linux kernel handled HID (Human Interface

Device) reports with an out-of-bounds Report ID. An attacker with physical
access to the system could use this flaw to crash the system or,
potentially, escalate their privileges on the system. (CVE-2013-2888,
Moderate)

This update also fixes the following bugs:

• A previous change to the sunrpc code introduced a race condition between

the rpc_wake_up_task() and rpc_wake_up_status() functions. A race between
threads operating on these functions could result in a deadlock situation,
subsequently triggering a "soft lockup" event and rendering the system
unresponsive. This problem has been fixed by re-ordering tasks in the RPC
wait queue. (BZ#1073731)

• Running a process in the background on a GFS2 file system could

sometimes trigger a glock recursion error that resulted in a kernel panic.
This happened when a readpage operation attempted to take a glock that had
already been held by another function. To prevent this error, GFS2 now
verifies whether the glock is already held when performing the readpage
operation. (BZ#1073953)

• A previous patch backport to the IUCV (Inter User Communication Vehicle)

code was incomplete. Consequently, when establishing an IUCV connection,
the kernel could, under certain circumstances, dereference a NULL pointer,
resulting in a kernel panic. A patch has been applied to correct this
problem by calling the proper function when removing IUCV paths.
(BZ#1077045)

In addition, this update adds the following enhancement:

• The lpfc driver had a fixed timeout of 60 seconds for SCSI task

management commands. With this update, the lpfc driver enables the user to
set this timeout within the range from 5 to 180 seconds. The timeout can
be changed by modifying the "lpfc_task_mgmt_tmo" parameter for the lpfc
driver. (BZ#1073123)

All kernel users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues 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
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 Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 1000451 - CVE-2013-2888 Kernel: HID: memory corruption flaw
• BZ - 1066055 - CVE-2012-6638 Kernel: net: tcp: potential DoS via SYN+FIN messages

CVEs

• CVE-2013-2888
• CVE-2012-6638

References

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