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Security Advisory Important: kernel-rt security and bug fix update

Advisory: RHSA-2013:0622-1
Type: Security Advisory
Severity: Important
Issued on: 2013-03-11
Last updated on: 2013-03-11
Affected Products: Red Hat Enterprise MRG v2 for Red Hat Enterprise Linux (version 6)
CVEs ( CVE-2012-4542


Updated kernel-rt packages that fix several security issues and three bugs
are now available for Red Hat Enterprise MRG 2.3.

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.

The kernel-rt 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 way file permission checks for the
"/dev/cpu/[x]/msr" files were performed in restricted root environments
(for example, when using a capability-based security model). A local user
with the ability to write to these files could use this flaw to escalate
their privileges to kernel level, for example, by writing to the
SYSENTER_EIP_MSR register. (CVE-2013-0268, Important)

* A race condition was found in the way the Linux kernel's ptrace
implementation handled PTRACE_SETREGS requests when the debuggee was woken
due to a SIGKILL signal instead of being stopped. A local, unprivileged
user could use this flaw to escalate their privileges. (CVE-2013-0871,

* An out-of-bounds access flaw was found in the way SOCK_DIAG_BY_FAMILY
Netlink messages were processed in the Linux kernel. A local, unprivileged
user could use this flaw to escalate their privileges. (CVE-2013-1763,

* It was found that the default SCSI command filter does not accommodate
commands that overlap across device classes. A privileged guest user could
potentially use this flaw to write arbitrary data to a LUN that is
passed-through as read-only. (CVE-2012-4542, Moderate)

* A flaw was found in the way the __skb_recv_datagram() function in the
Linux kernel processed payload-less socket buffers (skb) when the MSG_PEEK
option was requested. A local, unprivileged user could use this flaw to
cause a denial of service (infinite loop). (CVE-2013-0290, Moderate)

The CVE-2012-4542 issue was discovered by Paolo Bonzini of Red Hat.

This update also fixes the following bugs:

* There was high contention on run-queue lock when load balancing before
idling, causing latency spikes on high CPU core count systems. With this
update, IPI is used to send notification to cores with pending work, and
the cores push the work rather than trying to pull it, resolving this
issue. (BZ#858396)

* Previously, ACPI lock was converted to an rt_mutex, leading to a
traceback when scheduling while atomic. With this update, ACPI lock has
been converted back to a raw spinlock. (BZ#909965)

* Fibre Channel (FC)/iSCSI device state was set to off-line and after a
timeout, not set back to running. Such a device would not come back online
after a fast_io_fail or timeout. With this update, an explicit check for
the device being offline has been added, and the device is set back to
running when re-initializing, allowing devices to recover after a failure
or timeout. (BZ#912942)

Users should upgrade to these updated packages, which correct these issues.
The system must be rebooted for this update to take effect.


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

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.

Updated packages

Red Hat Enterprise MRG v2 for Red Hat Enterprise Linux (version 6)

File outdated by:  RHBA-2014:0381
    MD5: 14076ce2c04dd4ca1a839b4aa91768f0
SHA-256: c340f4f186c912a0095ec537dc07159de7d9d9e39565766fc527ee1c38f636ae
File outdated by:  RHBA-2014:0381
    MD5: 55e691ac8a8a6f663b78a6df4a9a8c8b
SHA-256: b67662ef478791560613fe988367ec7382c6a8caca257827699a473c8965fc4a
File outdated by:  RHBA-2014:0381
    MD5: 53b5be04a05f9147876ce4ed251b746d
SHA-256: c8e127e009f9f16d304ecff612526e099b0605c87dad7e726e5bc117d256cf9c
File outdated by:  RHBA-2014:0381
    MD5: 511a71a45f8f8e01fbc42fe96da9babb
SHA-256: 481d9d9da6ce09efa0e95b207101c9603579abc825ce582e5531ed74beae6cf9
File outdated by:  RHBA-2014:0381
    MD5: 850fc1a06c2d8daeb24afa8d818ca483
SHA-256: f773b1ffca3881d8c8ad1f0de28d97a57cd7ae06de735d633f4eed5801592cfe
File outdated by:  RHBA-2014:0381
    MD5: a8264c306bded7eaa00b659a629fe7be
SHA-256: e56a5163a1c2f177b7a28b1321d9589d7e26dbe15624878ab7b586a04b61376c
File outdated by:  RHBA-2014:0381
    MD5: d42eef3eb3d8d21f110325dd1c55c1fd
SHA-256: bcf335c5e18df8c6f93e54beea5c9b1394637f9b43242e34db23d1121338928a
File outdated by:  RHBA-2014:0381
    MD5: 19826650c726299359469463dd9b6468
SHA-256: 7b12bb159693c36bd20694d282118522a791daff33be0e9b72c51661792ac46a
File outdated by:  RHBA-2014:0381
    MD5: 3d89bc2ff4077deb6e17f97c2e0adbc1
SHA-256: 907cb1af86f83799da9ec144e8c01e7c91842ce5d6592f79928b18bfccb29d0b
File outdated by:  RHBA-2014:0381
    MD5: 342ad0a5f5788c436672d8e19058b779
SHA-256: d9c8acbeafccfa587e4f54bcbc887fdfda5d0405e5af19e353875c996760f860
File outdated by:  RHBA-2014:0381
    MD5: 27ed8471ad2855185dd89de4e3998ee0
SHA-256: 13d4b41f59b108df7f4c87cdeb65ccc21a5b48c8cd003725db820e88670d58d1
File outdated by:  RHBA-2014:0381
    MD5: 3755d04bef400807fec37e13df0c440a
SHA-256: a61e86c2a700e8a16d928b8118c5fc23c1b5b74caa5615dec06de7dc02483101
File outdated by:  RHBA-2014:0381
    MD5: 908daebeabb1f96d17d7ecd0ec6290d3
SHA-256: bfb0001f3e3b5ff013f140ac40d03f248075684c0a449b8606dc1a728f17bd1d
File outdated by:  RHBA-2014:0381
    MD5: c942ede584c7f02bd9905d3be0df5ebe
SHA-256: 36b008dbc7d96e8acb732c5d8752fa24943ecd56d909dae8498f7be75881624a
File outdated by:  RHBA-2014:0381
    MD5: 9c3d8e7192493a5fedd5c437a8962778
SHA-256: ea92a5f2d2f1b8c8d6e9de38874fbcc62187f836adf7f954a5623606ed10f9cf
File outdated by:  RHBA-2014:0381
    MD5: 8bbed153244fb201bcf08ea53a145f96
SHA-256: aa9fc2008ae8f5400a5cbd455ce8ceba1de3bf79fd8a9ddf86e00a27da2c64ff
File outdated by:  RHSA-2013:1490
    MD5: 5834a4abc3329dc5138da9dfe0b49410
SHA-256: 94bc98784c20bdcd3bca6e4a3a0bf38dc2145180fed9c41ca60f6b41f61b4a8d
(The unlinked packages above are only available from the Red Hat Network)

Bugs fixed (see bugzilla for more information)

858396 - latency issues on four-socket systems
875360 - CVE-2012-4542 kernel: block: default SCSI command filter does not accomodate commands overlap across device classes
908693 - CVE-2013-0268 kernel: x86/msr: /dev/cpu/*/msr local privilege escalation
911473 - CVE-2013-0290 kernel: net: infinite loop in __skb_recv_datagram()
911937 - CVE-2013-0871 kernel: race condition with PTRACE_SETREGS
915052 - CVE-2013-1763 kernel: sock_diag: out-of-bounds access to sock_diag_handlers[]


These packages are GPG signed by Red Hat for security. Our key and details on how to verify the signature are available from:

The Red Hat security contact is More contact details at