Re: Linux kernel: missing CPU-state sanitation during task-switch causes DOS / privilege escalation

[cve-assign () mitre org]

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> local DOS in the end. One some architectures, privilege escalation
> under non-common circumstances is possible,


> http://www.halfdog.net/Security/2013/Vm86SyscallTaskSwitchKernelPanic/
>
> A closer analysis of the initial vm86-syscall problem showed, that
> root cause was missing handling of FPU exceptions during task switch
> at emms instruction. That was confirmed by Borislav Petkov. According
> to discussion on LKML, the problem should affect only AMD CPUs, both
> in i386 and amd64-mode ...


> https://lkml.org/lkml/2014/1/9/637
>
> From: Linus Torvalds
> Date: Fri, 10 Jan 2014 08:42:33 +0800
>
> Looking at this, I think this is just a bug in our
> restore_fpu_checking() hackery for X86_FEATURE_FXSAVE_LEAK..

Use CVE-2014-1438.

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CVE assignment team, MITRE CVE Numbering Authority
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