(RHSA-2014:0433) Moderate: kernel security, bug fix, and enhancement update

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

• A flaw was found in the way the Linux kernel’s TCP/IP protocol suite
  implementation handled TCP packets with both the SYN and FIN flags set.
  A remote attacker could use this flaw to consume an excessive amount of
  resources on the target system, potentially resulting in a denial of
  service. (CVE-2012-6638, Moderate)

• A flaw was found in the way the Linux kernel handled HID (Human Interface
  Device) reports with an out-of-bounds Report ID. 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-2013-2888,
  Moderate)

This update also fixes the following bugs:

• A previous change to the sunrpc code introduced a race condition between
  the rpc_wake_up_task() and rpc_wake_up_status() functions. A race between
  threads operating on these functions could result in a deadlock situation,
  subsequently triggering a “soft lockup” event and rendering the system
  unresponsive. This problem has been fixed by re-ordering tasks in the RPC
  wait queue. (BZ#1073731)

• Running a process in the background on a GFS2 file system could
  sometimes trigger a glock recursion error that resulted in a kernel panic.
  This happened when a readpage operation attempted to take a glock that had
  already been held by another function. To prevent this error, GFS2 now
  verifies whether the glock is already held when performing the readpage
  operation. (BZ#1073953)

• A previous patch backport to the IUCV (Inter User Communication Vehicle)
  code was incomplete. Consequently, when establishing an IUCV connection,
  the kernel could, under certain circumstances, dereference a NULL pointer,
  resulting in a kernel panic. A patch has been applied to correct this
  problem by calling the proper function when removing IUCV paths.
  (BZ#1077045)

In addition, this update adds the following enhancement:

• The lpfc driver had a fixed timeout of 60 seconds for SCSI task
  management commands. With this update, the lpfc driver enables the user to
  set this timeout within the range from 5 to 180 seconds. The timeout can
  be changed by modifying the “lpfc_task_mgmt_tmo” parameter for the lpfc
  driver. (BZ#1073123)

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