(RHSA-2010:0076) Important: kernel security and bug fix update

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

This update fixes the following security issues:

• an array index error was found in the gdth driver in the Linux kernel. A
  local user could send a specially-crafted IOCTL request that would cause a
  denial of service or, possibly, privilege escalation. (CVE-2009-3080,
  Important)

• a flaw was found in the collect_rx_frame() function in the HiSax ISDN
  driver (hfc_usb) in the Linux kernel. An attacker could use this flaw to
  send a specially-crafted HDLC packet that could trigger a buffer out of
  bounds, possibly resulting in a denial of service. (CVE-2009-4005,
  Important)

• permission issues were found in the megaraid_sas driver (for SAS based
  RAID controllers) in the Linux kernel. The “dbg_lvl” and “poll_mode_io”
  files on the sysfs file system (“/sys/”) had world-writable permissions.
  This could allow local, unprivileged users to change the behavior of the
  driver. (CVE-2009-3889, CVE-2009-3939, Moderate)

• a buffer overflow flaw was found in the hfs_bnode_read() function in the
  HFS file system implementation in the Linux kernel. This could lead to a
  denial of service if a user browsed a specially-crafted HFS file system,
  for example, by running “ls”. (CVE-2009-4020, Low)

This update also fixes the following bugs:

• if a process was using ptrace() to trace a multi-threaded process, and
  that multi-threaded process dumped its core, the process performing the
  trace could hang in wait4(). This issue could be triggered by running
  “strace -f” on a multi-threaded process that was dumping its core,
  resulting in the strace command hanging. (BZ#555869)

• a bug in the ptrace() implementation could have, in some cases, caused
  ptrace_detach() to create a zombie process if the process being traced
  was terminated with a SIGKILL signal. (BZ#555869)

• the RHSA-2010:0020 update resolved an issue (CVE-2009-4537) in the
  Realtek r8169 Ethernet driver. This update implements a better solution for
  that issue. Note: This is not a security regression. The original fix was
  complete. This update is adding the official upstream fix. (BZ#556406)

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.