Issued:

2012-03-27

Updated:

2012-03-27

RHBA-2012:0424 - kernel bug fix update

Synopsis

kernel bug fix update

Type/Severity

Bug Fix Advisory

Topic

Updated kernel packages that fix multiple bugs are now available for Red Hat Enterprise Linux 6 Extended Update Support.

Description

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

This update fixes the following bugs:

• Socket callbacks use the svc_xprt_enqueue() function to add sockets to the sp_sockets list. In normal operation, a server thread will later take the socket off that list. Previously, on the nfsd daemon shutdown, still-running svc_xprt_enqueue() could re-add a socket to the sp_sockets list just before it was deleted. Consequently, the system could terminate unexpectedly due to memory corruption in the sunrpc module. With this update, the XPT_BUSY flag is set on every socket before shutdown and svc_xprt_enqueue() now checks this flag, thus preventing this bug. (BZ#789912)

• Due to a race condition, running the "ifenslave -d bond0 eth0" command to remove the slave interface from the bonding device could cause the system to crash when a networking packet was being received at the same time. With this update, the race condition has been fixed and the system no longer crashes under these circumstances. (BZ#795332)

• In rare cases, a BUG_ON() macro could be triggered, causing the nfsd daemon to fail. The BUG_ON() macro checked the xpt_pool field, which was not actually used for anything. This update removes both the BUG_ON() macro and the xpt_pool field, fixing the problem. (BZ#795337)

• An insufficiently well-designed calculation in the CPU accelerator in the previous version of the kernel packages caused an arithmetic overflow in the sched_clock() function when system uptime exceeded 208.5 days. This overflow led to a kernel panic on systems using the Time Stamp Counter (TSC) or Virtual Machine Interface (VMI) clock source. This update corrects the aforementioned calculation so that this arithmetic overflow and kernel panic can no longer occur under these circumstances. (BZ#795817)

• On a system that created and deleted lots of dynamic devices, the 31-bit Linux ifindex object failed to fit in the 16-bit macvtap minor range, resulting in unusable macvtap devices. The problem primarily occurred in a libvirt-controlled environment when many virtual machines were started or restarted, and caused libvirt to report the following message:

  Error starting domain: cannot open macvtap tap device /dev/tap222364: No such device or address

With this update, the macvtap's minor device number allocation has been modified so that virtual machines can now be started and restarted as expected in the described scenario. (BZ#796826)

• The dm_mirror module can send discard requests. However, the dm_io interface did not support discard requests, and running an LVM mirror over a discard-enabled device led to a kernel panic. This update adds support for the discard requests to the dm_io interface, so that kernel panics no longer occur in the described scenario. (BZ#799942)

All users of kernel are advised to upgrade to these updated packages, which fix these bugs. 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/knowledge/articles/11258

Affected Products

Updated Packages

• kernel-2.6.32-131.26.1.el6.s390x.rpm
• perf-debuginfo-2.6.32-131.26.1.el6.x86_64.rpm
• kernel-headers-2.6.32-131.26.1.el6.s390x.rpm
• kernel-debuginfo-2.6.32-131.26.1.el6.s390x.rpm
• kernel-2.6.32-131.26.1.el6.i686.rpm
• kernel-devel-2.6.32-131.26.1.el6.s390x.rpm
• kernel-debug-2.6.32-131.26.1.el6.s390x.rpm
• kernel-debug-2.6.32-131.26.1.el6.x86_64.rpm
• kernel-kdump-devel-2.6.32-131.26.1.el6.s390x.rpm
• perf-2.6.32-131.26.1.el6.x86_64.rpm
• kernel-kdump-2.6.32-131.26.1.el6.s390x.rpm
• kernel-headers-2.6.32-131.26.1.el6.i686.rpm
• kernel-debuginfo-common-s390x-2.6.32-131.26.1.el6.s390x.rpm
• kernel-debug-debuginfo-2.6.32-131.26.1.el6.x86_64.rpm
• kernel-debug-2.6.32-131.26.1.el6.i686.rpm
• kernel-devel-2.6.32-131.26.1.el6.i686.rpm
• perf-debuginfo-2.6.32-131.26.1.el6.i686.rpm
• kernel-debug-devel-2.6.32-131.26.1.el6.x86_64.rpm
• kernel-bootwrapper-2.6.32-131.26.1.el6.ppc64.rpm
• kernel-2.6.32-131.26.1.el6.ppc64.rpm
• kernel-debuginfo-common-i686-2.6.32-131.26.1.el6.i686.rpm
• kernel-debuginfo-2.6.32-131.26.1.el6.i686.rpm
• perf-2.6.32-131.26.1.el6.i686.rpm
• kernel-headers-2.6.32-131.26.1.el6.x86_64.rpm
• kernel-kdump-debuginfo-2.6.32-131.26.1.el6.s390x.rpm
• kernel-firmware-2.6.32-131.26.1.el6.noarch.rpm
• kernel-headers-2.6.32-131.26.1.el6.ppc64.rpm
• perf-2.6.32-131.26.1.el6.s390x.rpm
• kernel-debuginfo-common-ppc64-2.6.32-131.26.1.el6.ppc64.rpm
• kernel-debug-devel-2.6.32-131.26.1.el6.s390x.rpm
• kernel-debuginfo-2.6.32-131.26.1.el6.x86_64.rpm
• kernel-2.6.32-131.26.1.el6.x86_64.rpm
• kernel-2.6.32-131.26.1.el6.src.rpm
• kernel-debug-devel-2.6.32-131.26.1.el6.ppc64.rpm
• kernel-debug-debuginfo-2.6.32-131.26.1.el6.ppc64.rpm
• kernel-debug-devel-2.6.32-131.26.1.el6.i686.rpm
• kernel-debuginfo-2.6.32-131.26.1.el6.ppc64.rpm
• kernel-devel-2.6.32-131.26.1.el6.x86_64.rpm
• perf-debuginfo-2.6.32-131.26.1.el6.ppc64.rpm
• kernel-debug-debuginfo-2.6.32-131.26.1.el6.s390x.rpm
• perf-debuginfo-2.6.32-131.26.1.el6.s390x.rpm
• kernel-devel-2.6.32-131.26.1.el6.ppc64.rpm
• kernel-doc-2.6.32-131.26.1.el6.noarch.rpm
• kernel-debuginfo-common-x86_64-2.6.32-131.26.1.el6.x86_64.rpm
• kernel-debug-2.6.32-131.26.1.el6.ppc64.rpm
• kernel-debug-debuginfo-2.6.32-131.26.1.el6.i686.rpm
• perf-2.6.32-131.26.1.el6.ppc64.rpm

Fixes

(none)

CVEs

(none)

References

(none)

Additional information

• The Red Hat security contact is This content is not included.secalert@redhat.com. More contact details at https://access.redhat.com/security/team/contact/.
• Offline Security Data data is available for integration with other systems. See Offline Security Data API to get started.