Ubuntu: USN-4756-1 Critical: Linux Kernel Denial of Service Issues

CVE-2013-6885

It was discovered that under specific circumstances, a combination
of write operations to write-combined memory and locked CPU
instructions may cause a core hang on AMD 16h 00h through 0Fh
processors. A local user can use this flaw to mount a denial of
service (system hang) via a crafted application.

For more information please refer to the AMD CPU erratum 793 in
https://www.amd.com/en/search/documentation/hub.html#sortCriteria=%40amd_release_date%20descending&f-amd_archive_status=Active&f-amd_audience=Technical

CVE-2014-8133

It was found that the espfix funcionality can be bypassed by
installing a 16-bit RW data segment into GDT instead of LDT (which
espfix checks for) and using it for stack. A local unprivileged user
could potentially use this flaw to leak kernel stack addresses and
thus allowing to bypass the ASLR protection mechanism.

CVE-2014-9419

It was found that on Linux kernels compiled with the 32 bit
interfaces (CONFIG...