CVE-2012-0045

Stefan Bader stefan.bader at canonical.com
Wed Mar 14 22:18:36 UTC 2012


32bit guests will crash (and 64bit guests may behave in a
wrong way) for example by simply executing following
nasm-demo-application:
The reason seems a missing "invalid opcode"-trap (int6) for the
syscall opcode "0f05", which is not available on Intel CPUs
within non-longmodes, as also on some AMD CPUs within legacy-mode.
(depending on CPU vendor, MSR_EFER and cpuid)

Problem got introduced in 2.6.32 (so Hardy is not affected) and
recently fixed in a 3.3-rc.
For Precise a simple cherry-pick of the two patches works. Previous
releases require a increasing amount of tweaking. Following this
email are the patches for Lucid till Precise.
Since KVM virtualization is not an option for ARM and neither EC2,
only the master branches should require this. If I did not forget
something.

Changes tested on 32bit hosts/32bit guest for all releases and
additionally on a 64bit host/32bit+64bit guest for Lucid.

-Stefan




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