RHSA-2011:0928: Moderate: kernel security and bug fix update

The kernel packages contain the Linux kernel, the core of any Linuxoperating system.This update fixes the following security issues: It was found that the receive hook in the ipipinit() function in the ipip module, and in the ipgreinit() function in the ipgre module, couldbe called before network namespaces setup is complete. If packets werereceived at the time the ipip or ipgre module was still being loaded intothe kernel, it could cause a denial of service. (CVE-2011-1767,CVE-2011-1768, Moderate) It was found that an mmap() call with the MAPPRIVATE flag on "/dev/zero" would create transparent hugepages and trigger a certain robustness check.A local, unprivileged user could use this flaw to cause a denial ofservice. (CVE-2011-2479, Moderate)This update also fixes various bugs. Documentation for these bug fixes willbe available shortly from the Technical Notes document linked to in theReferences section.Users should upgrade to these updated packages, which contain backportedpatches to resolve these issues, and fix the bugs noted in the TechnicalNotes. The system must be rebooted for this update to take effect.