(RHSA-2010:0161) Important: kernel-rt security and bug fix update

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

This update fixes the following security issues:

• a deficiency was found in the fasync_helper() implementation. This could
  allow a local, unprivileged user to leverage a use-after-free of locked,
  asynchronous file descriptors to cause a denial of service or privilege
  escalation. (CVE-2009-4141, Important)

• multiple flaws were found in the mmap and mremap implementations. A
  local, unprivileged user could use these flaws to cause a local denial of
  service or escalate their privileges. (CVE-2010-0291, Important)

• a missing boundary check was found in the do_move_pages() function in the
  memory migration functionality. A local user could use this flaw to cause a
  local denial of service or an information leak. (CVE-2010-0415, Important)

• a NULL pointer dereference flaw was found in the ip6_dst_lookup_tail()
  function. An attacker on the local network could trigger this flaw by
  sending IPv6 traffic to a target system, leading to a system crash (kernel
  OOPS) if dst->neighbour is NULL on the target system when receiving an IPv6
  packet. (CVE-2010-0437, Important)

• a NULL pointer dereference flaw was found in the Fast Userspace Mutexes
  (futexes) implementation. The unlock code path did not check if the futex
  value associated with pi_state->owner had been modified. A local user could
  use this flaw to modify the futex value, possibly leading to a denial of
  service or privilege escalation when the pi_state->owner pointer is
  dereferenced. (CVE-2010-0622, Important)

• an information leak was found in the print_fatal_signal() implementation.
  When “/proc/sys/kernel/print-fatal-signals” is set to 1 (the default value
  is 0), memory that is reachable by the kernel could be leaked to
  user-space. This issue could also result in a system crash. Note that this
  flaw only affected the i386 architecture. (CVE-2010-0003, Moderate)

• a flaw was found in the kernel connector implementation. A local,
  unprivileged user could trigger this flaw by sending an arbitrary amount of
  notification requests using specially-crafted netlink messages, resulting
  in a denial of service. (CVE-2010-0410, Moderate)

• missing capability checks were found in the ebtables implementation, used
  for creating an Ethernet bridge firewall. This could allow a local,
  unprivileged user to bypass intended capability restrictions and modify
  ebtables rules. (CVE-2010-0007, Low)

This update also fixes the following bugs:

• references were missing for two LSI MegaRAID SAS controllers already
  supported by the kernel, preventing systems using these controllers from
  booting. (BZ#554664)

• a typo in the fix for CVE-2009-2691 resulted in gdb being unable to read
  core files created by gcore. (BZ#554965)

• values for certain pointers used by the kernel, which should be
  undereferencable, could potentially be abused when a kernel OOPS occurs.
  Values that are harder to dereference are now used. (BZ#555227)

• this update redesigns the locking scheme of the TTY process group
  (tty->pgrp) structure, due to race conditions introduced when tty->pgrp
  started using struct pid instead of pid_t. (BZ#559101)

• the way the NFS kernel server used iget() and the way in which it kept
  its cache of inode information, could have led to (mainly on busy file
  servers) inconsistencies between the local file system and the file system
  being served to clients. (BZ#561275)

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