(RHSA-2010:0380) Important: kernel security and bug fix update

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

Security fixes:

• a race condition was found in the mac80211 implementation, a framework
  used for writing drivers for wireless devices. An attacker could trigger
  this flaw by sending a Delete Block ACK (DELBA) packet to a target system,
  resulting in a remote denial of service. Note: This issue only affected
  users on 802.11n networks, and that also use the iwlagn driver with Intel
  wireless hardware. (CVE-2009-4027, Important)

• a use-after-free flaw was found in the tcp_rcv_state_process() function
  in the Linux kernel TCP/IP protocol suite implementation. If a system using
  IPv6 had the IPV6_RECVPKTINFO option set on a listening socket, a remote
  attacker could send an IPv6 packet to that system, causing a kernel panic
  (denial of service). (CVE-2010-1188, Important)

• a flaw was found in the gfs2_lock() implementation. The GFS2 locking code
  could skip the lock operation for files that have the S_ISGID bit
  (set-group-ID on execution) in their mode set. A local, unprivileged user
  on a system that has a GFS2 file system mounted could use this flaw to
  cause a kernel panic (denial of service). (CVE-2010-0727, Moderate)

• a divide-by-zero flaw was found in the ext4 file system code. A local
  attacker could use this flaw to cause a denial of service by mounting a
  specially-crafted ext4 file system. (CVE-2009-4307, Low)

Bug fixes:

• if a program that calls posix_fadvise() were compiled on x86, and then
  run on a 64-bit system, that program could experience various problems,
  including performance issues and the call to posix_fadvise() failing,
  causing the program to not run as expected or even abort. With this update,
  when such programs attempt to call posix_fadvise() on 64-bit systems,
  sys32_fadvise64() is called instead, which resolves this issue. This update
  also fixes other 32-bit system calls that were mistakenly called on 64-bit
  systems (including systems running the kernel-xen kernel). (BZ#569597)

• on some systems able to set a P-State limit via the BIOS, it was not
  possible to set the limit to a higher frequency if the system was rebooted
  while a low limit was set:
  “/sys/devices/system/cpu/cpu[x]/cpufreq/scaling_max_freq” would retain the
  low limit in these situations. With this update, limits are correctly set,
  even after being changed after a system reboot. (BZ#569727)

• certain Intel ICH hardware (using the e1000e driver) has an NFS filtering
  capability that did not work as expected, causing memory corruption, which
  could lead to kernel panics, or other unexpected behavior. In a reported
  case, a panic occurred when running NFS connection tests. This update
  resolves this issue by disabling the filtering capability. (BZ#569797)

• if “open(/proc/[PID]/[xxxx])” was called at the same time the process was
  exiting, the call would fail with an EINVAL error (an incorrect error for
  this situation). With this update, the correct error, ENOENT, is returned
  in this situation. (BZ#571362)

• multiqueue is used for transmitting data, but a single queue transmit
  ON/OFF scheme was used. This led to a race condition on systems with the
  bnx2x driver in situations where one queue became full, but not stopped,
  and the other queue enabled transmission. With this update, only a single
  queue is used. (BZ#576951)

• the “/proc/sys/vm/mmap_min_addr” tunable helps prevent unprivileged
  users from creating new memory mappings below the minimum address. The
  sysctl value for mmap_min_addr could be changed by a process or user that
  has an effective user ID (euid) of 0, even if the process or user does not
  have the CAP_SYS_RAWIO capability. This update adds a capability check for
  the CAP_SYS_RAWIO capability before allowing the mmap_min_addr value to be
  changed. (BZ#577206)

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.