(RHSA-2015:0284) Important: kernel security and bug fix update

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

• A race condition flaw was found in the way the Linux kernel’s KVM
  subsystem handled PIT (Programmable Interval Timer) emulation. A guest user
  who has access to the PIT I/O ports could use this flaw to crash the host.
  (CVE-2014-3611, Important)

• A flaw was found in the way the Linux kernel’s SCTP implementation
  validated INIT chunks when performing Address Configuration Change
  (ASCONF). A remote attacker could use this flaw to crash the system by
  sending a specially crafted SCTP packet to trigger a NULL pointer
  dereference on the system. (CVE-2014-7841, Important)

• A flaw was found in the way the ipc_rcu_putref() function in the Linux
  kernel’s IPC implementation handled reference counter decrementing.
  A local, unprivileged user could use this flaw to trigger an Out of Memory
  (OOM) condition and, potentially, crash the system. (CVE-2013-4483,
  Moderate)

• A memory corruption flaw was found in the way the USB ConnectTech
  WhiteHEAT serial driver processed completion commands sent via USB Request
  Blocks buffers. 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-2014-3185, Moderate)

• It was found that the Linux kernel’s KVM subsystem did not handle the VM
  exits gracefully for the invept (Invalidate Translations Derived from EPT)
  and invvpid (Invalidate Translations Based on VPID) instructions. On hosts
  with an Intel processor and invept/invppid VM exit support, an unprivileged
  guest user could use these instructions to crash the guest. (CVE-2014-3645,
  CVE-2014-3646, Moderate)

• A flaw was found in the way the Linux kernel’s netfilter subsystem
  handled generic protocol tracking. As demonstrated in the Stream Control
  Transmission Protocol (SCTP) case, a remote attacker could use this flaw to
  bypass intended iptables rule restrictions when the associated connection
  tracking module was not loaded on the system. (CVE-2014-8160, Moderate)

Red Hat would like to thank Lars Bull of Google for reporting
CVE-2014-3611, Vladimir Davydov (Parallels) for reporting CVE-2013-4483,
and the Advanced Threat Research team at Intel Security for reporting
CVE-2014-3645 and CVE-2014-3646. The CVE-2014-7841 issue was discovered by
Liu Wei of Red Hat.

Bug fixes:

• When forwarding a packet, the iptables target TCPOPTSTRIP used the
  tcp_hdr() function to locate the option space. Consequently, TCPOPTSTRIP
  located the incorrect place in the packet, and therefore did not match
  options for stripping. TCPOPTSTRIP now uses the TCP header itself to locate
  the option space, and the options are now properly stripped. (BZ#1172026)

• The ipset utility computed incorrect values of timeouts from an old IP
  set, and these values were then supplied to a new IP set. A resize on an IP
  set with a timeouts option enabled could then supply corrupted data from an
  old IP set. This bug has been fixed by properly reading timeout values from
  an old set before supplying them to a new set. (BZ#1172763)

• Incorrect processing of errors from the BCM5719 LAN controller could
  result in incoming packets being dropped. Now, received errors are handled
  properly, and incoming packets are no longer randomly dropped. (BZ#1180405)

• When the NVMe driver allocated a name-space queue, it was recognized as a
  request-based driver, whereas it was a BIO-based driver. While trying to
  access data during the loading of NVMe along with a request-based DM
  device, the system could terminate unexpectedly or become unresponsive.
  Now, NVMe does not set the QUEUE_FLAG_STACKABLE flag during the allocation
  of a name-space queue, and the system no longer attempts to insert a
  request into the queue, preventing a crash. (BZ#1180554)

All kernel users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues. The system must be
rebooted for this update to take effect.