Scientific Linux Security Update : kernel on SL5.x i386/x86_64

This script is Copyright (C) 2012 Tenable Network Security, Inc.


Synopsis :

The remote Scientific Linux host is missing one or more security
updates.

Description :

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

Security fix :

- The fix for CVE-2011-1083 introduced a flaw in the way
the Linux kernel's Event Poll (epoll) subsystem handled
resource clean up when an ELOOP error code was returned.
A local, unprivileged user could use this flaw to cause
a denial of service. (CVE-2012-3375, Moderate)

Bug fixes :

- The qla2xxx driver handled interrupts for QLogic Fibre
Channel adapters incorrectly due to a bug in a test
condition for MSI-X support. This update corrects the
bug and qla2xxx now handles interrupts as expected.

- A process scheduler did not handle RPC priority wait
queues correctly. Consequently, the process scheduler
failed to wake up all scheduled tasks as expected after
RPC timeout, which caused the system to become
unresponsive and could significantly decrease system
performance. This update modifies the process scheduler
to handle RPC priority wait queues as expected. All
scheduled tasks are now properly woken up after RPC
timeout and the system behaves as expected.

- The kernel version 2.6.18-308.4.1.el5 contained several
bugs which led to an overrun of the NFS server page
array. Consequently, any attempt to connect an NFS
client running on Scientific Linux 5.8 to the NFS server
running on the system with this kernel caused the NFS
server to terminate unexpectedly and the kernel to
panic. This update corrects the bugs causing NFS page
array overruns and the kernel no longer crashes in this
scenario.

- An insufficiently designed calculation in the CPU
accelerator in the previous kernel caused an arithmetic
overflow in the sched_clock() function when system
uptime exceeded 208.5 days. This overflow led to a
kernel panic on the systems using the Time Stamp Counter
(TSC) or Virtual Machine Interface (VMI) clock source.
This update corrects the calculation so that this
arithmetic overflow and kernel panic can no longer occur
under these circumstances.

Note: This advisory does not include a fix for this bug for the 32-bit
architecture.

- Under memory pressure, memory pages that are still a
part of a checkpointing transaction can be invalidated.
However, when the pages were invalidated, the journal
head was re-filed onto the transactions' 'forget' list,
which caused the current running transaction's block to
be modified. As a result, block accounting was not
properly performed on that modified block because it
appeared to have already been modified due to the
journal head being re-filed. This could trigger an
assertion failure in the 'journal_commit_transaction()'
function on the system. The 'b_modified' flag is now
cleared before the journal head is filed onto any
transaction
assertion failures no longer occur.

- When running more than 30 instances of the cclengine
utility concurrently on IBM System z with IBM
Communications Controller for Linux, the system could
become unresponsive. This was caused by a missing
wake_up() function call in the qeth_release_buffer()
function in the QETH network device driver. This update
adds the missing wake_up() function call and the system
now responds as expected in this scenario.

- Recent changes removing support for the Flow Director
from the ixgbe driver introduced bugs that caused the
RSS (Receive Side Scaling) functionality to stop working
correctly on Intel 82599EB 10 Gigabit Ethernet network
devices. This update corrects the return code in the
ixgbe_cache_ring_fdir function and setting of the
registers that control the RSS redirection table. Also,
obsolete code related to Flow Director support has been
removed. The RSS functionality now works as expected on
these devices.

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.

See also :

http://www.nessus.org/u?d99753da

Solution :

Update the affected packages.

Risk factor :

Medium / CVSS Base Score : 4.9
(CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:C)

Family: Scientific Linux Local Security Checks

Nessus Plugin ID: 61360 ()

Bugtraq ID:

CVE ID: CVE-2012-3375