(RHSA-2012:0481) Moderate: kernel security, bug fix, and enhancement update

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

This update fixes the following security issues:

• Numerous reference count leaks were found in the Linux kernel’s block
  layer I/O context handling implementation. This could allow a local,
  unprivileged user to cause a denial of service. (CVE-2012-0879,
  Moderate)

• A flaw was found in the Linux kernel’s cifs_lookup() implementation.
  POSIX open during lookup should only be supported for regular files. When
  non-regular files (for example, a named (FIFO) pipe or other special files)
  are opened on lookup, it could cause a denial of service. (CVE-2012-1090,
  Moderate)

• It was found that the Linux kernel’s register set (regset) common
  infrastructure implementation did not check if the required get and set
  handlers were initialized. A local, unprivileged user could use this flaw
  to cause a denial of service by performing a register set operation with a
  ptrace() PTRACE_SETREGSET or PTRACE_GETREGSET request. (CVE-2012-1097,
  Moderate)

Red Hat would like to thank H. Peter Anvin for reporting CVE-2012-1097.

This update also fixes several bugs and adds various enhancements.
Documentation for these changes will be available shortly from the
Technical Notes document linked to in the References section.

Users should upgrade to these updated packages, which contain backported
patches to correct these issues, and fix the bugs and add the enhancements
noted in the Technical Notes. The system must be rebooted for this update
to take effect.