Bug Fix Advisory Red Hat Enterprise MRG Realtime 2.1 kernel bug fix update

Advisory: RHBA-2012:0496-1
Type: Bug Fix Advisory
Severity: N/A
Issued on: 2012-04-18
Last updated on: 2012-04-18
Affected Products: Red Hat Enterprise MRG v2 for Red Hat Enterprise Linux (version 6)
CVEs (cve.mitre.org): CVE-2011-1083


Updated kernel-rt packages that fix several bugs are now available for Red Hat
Enterprise MRG 2.1.

The kernel-rt packages contain the Linux kernel, the core of any Linux operating

This update provides a build of the kernel-rt package for MRG 2.1, which is
layered on Red Hat Enterprise Linux 6.

This update fixes the following bugs:

* Previously, while working with an open file, the epoll kernel code was calling
poll operations of another open file without holding the file's lock.
Consequently, a deadlock in the code could occur when using the system console.
Now, an upstream patch to use the ep_poll_nested() function has been provided
and the system console now works correctly in the described scenario.

* The i7core_edac code did multiple probes for the same hardware component. As a
consequence, boot time error message about the code being unable to create a
duplicate file in the /sys/devices/ directory was returned. With this update,
duplicate probe code has been removed and the error messages are no longer
returned in the described scenario. (BZ#773746)

* A previous Realtime work queue patch introduced a race conditions in the CPU
hotplug code. Consequently, the system could become unresponsive in this code.
This update reverts a few past updates to the work queue, which turned out to be
unnecessary, and the hangs no longer occur in the described scenario.

* The CONFIG_CC_OPTIMIZE_FOR_SIZE configuration parameter, which was previously
introduced to MRG Realtime, caused the gcc compiler to produce code prone to
cache line bouncing. As a result, the kernel performance was decreased. This
update turns off this parameter, thus improving cache utilization and
performance. (BZ#796297)

* Previously, configuration files in MRG Realtime and Red Hat Enterprise Linux 6
were not synchronized regarding modules and built-ins. Consequently, the
mkinitrd daemon failed to find code that was part of a module in Red Hat
Enterprise Linux 6 but part of a built-in in MRG Realtime. Now, the
configuration files have been synchronized between these two products and
mkinitrd correctly finds and sets up kernel components such as kdump.
(BZ#804119, BZ#756631)

Users of the Realtime capabilities of Red Hat Enterprise MRG 2.1, which is
layered on Red Hat Enterprise Linux 6, are advised to upgrade to these updated
packages, which fix these bugs. Note that 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

Updated packages

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

File outdated by:  RHSA-2017:1647
    MD5: 6fe5799c0114a437d6bdf550c6d4c294
SHA-256: 280f98ee0ce981b6cabde82bcb5caf6c9ac8e3241188b0dddc1507e4686c1606
File outdated by:  RHSA-2017:1647
    MD5: bf4652c4f524d98e59e072edc7a4430e
SHA-256: d633b1a68907bcd8917d89e3ed52e3d7c5954f535c66f402846b7247151e957a
File outdated by:  RHSA-2017:1647
    MD5: ce0e6e8cce2eeadffd8566c540e9ad19
SHA-256: 3fabbd4274fe4a28aee19b6cef3fd25688e5ba1889b473fb26449e3d14ae1e31
File outdated by:  RHSA-2017:1647
    MD5: dca0d3f763eace76d4903e679a808ba7
SHA-256: de8a72ce825664269a6b872e4534582611da86272c349f751eb7ae61c7ea58ed
File outdated by:  RHSA-2017:1647
    MD5: 3ea6772f15954dc865d331802dd15158
SHA-256: 98de4384d42180c4b32a1575d8e533de53441fb2671b1a2903d1593d471f5a8e
File outdated by:  RHSA-2017:1647
    MD5: ad299e5d21e0877de62e11140aa05019
SHA-256: ee2882ab5141ca4403be810478313cd139891dd89a556be1f4925965167e35d8
File outdated by:  RHSA-2017:1647
    MD5: 556bccd810fd4c4c886fe6b1c306e164
SHA-256: 047051e92eed373e87c5bcdbf7b348beb19251b11d9e4eca315975c2116a55df
File outdated by:  RHSA-2017:1647
    MD5: b4e9b0b688728bdf3a3d02a4c2b3a553
SHA-256: b55df5967d831f01129ebca8f1d824ec72b0ef59b75c9e1820812d0e9945230e
File outdated by:  RHSA-2017:1647
    MD5: c3d6121ae48b45c9370de59fd5ec9a45
SHA-256: e4555891a03f8ed7af0b2809a5aca23ab91155b628e88955fb1be298ace68588
File outdated by:  RHSA-2017:1647
    MD5: e02721f3993de80ca72c938576bbea92
SHA-256: 4a2fd568e21c24ab9395aad6e55dfb2863ed8f24aa6b5e9fc82142816f85d821
File outdated by:  RHSA-2017:1647
    MD5: e5fd916165a9fe04b25c95e5a5b2dc33
SHA-256: c71555d4d8c4dfe4f53320d9b8e8d3255d83874c4528fbf2c877cfc85e96f14f
File outdated by:  RHSA-2017:1647
    MD5: 7aa6d758029748d645f1924bd985fac4
SHA-256: 08cd9e86b3b7f13aeb19d24aec01c907c6563e16a44ee2c7a6b7b2da300043cf
File outdated by:  RHSA-2017:1647
    MD5: 7c6ed33d8eefad4ed801bc1c42aaea78
SHA-256: 173583fc3bffcab8eec11a70d01c67597d55ce52f2d9a050ee27f4f81f02c66d
File outdated by:  RHSA-2017:1647
    MD5: aeb3e71cf0b866004489b47e69e19649
SHA-256: c80f027de83aa63fb9b1327b51e0fe4db66ff97e408d362f33d1521efc0ca191
File outdated by:  RHSA-2017:1647
    MD5: 01162a560aa5d829496a440c70c14a7d
SHA-256: e013ed27346ffe7541c2cf5847011639dc8dab5e03e9d9fd634f49a831a075ec
File outdated by:  RHSA-2017:1647
    MD5: f750fcf818cb51a656ea17ef6e65c0c9
SHA-256: 0e4ba49a14e3eb8c62ada9d250d0a6f0473d693c373cd6799497e2c1b1039d36
(The unlinked packages above are only available from the Red Hat Network)

Bugs fixed (see bugzilla for more information)

675885 - kernel: epoll: Prevent deadlock through unsafe ->f_op->poll() calls [mrg-2.1]
787331 - System hang running Java tests on 3.0.9-rt26.45.el6rt.x86_64 kernel


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The Red Hat security contact is secalert@redhat.com. More contact details at http://www.redhat.com/security/team/contact/