Re: KASAN vs. boot-time switching between 4- and 5-level paging

[Andrey Ryabinin]

On 07/11/2017 08:03 PM, Kirill A. Shutemov wrote:
> On Tue, Jul 11, 2017 at 07:45:48PM +0300, Andrey Ryabinin wrote:
>> On 07/11/2017 06:15 PM, Andrey Ryabinin wrote:
>>>
>>> I reproduced this, and this is kasan bug:
>>>
>>>    â0xffffffff84864897 <x86_early_init_platform_quirks+5>   mov    $0xffffffff83f1d0b8,%rdi 
>>>    â0xffffffff8486489e <x86_early_init_platform_quirks+12>  movabs $0xdffffc0000000000,%rax 
>>>    â0xffffffff848648a8 <x86_early_init_platform_quirks+22>  push   %rbp
>>>    â0xffffffff848648a9 <x86_early_init_platform_quirks+23>  mov    %rdi,%rdx  
>>>    â0xffffffff848648ac <x86_early_init_platform_quirks+26>  shr    $0x3,%rdx
>>>    â0xffffffff848648b0 <x86_early_init_platform_quirks+30>  mov    %rsp,%rbp
>>>   >â0xffffffff848648b3 <x86_early_init_platform_quirks+33>  mov    (%rdx,%rax,1),%al
>>>
>>> we crash on the last move which is a read from shadow
>>
>>
>> Ughh, I forgot about phys_base.
> 
> Thanks! Works for me.
> 
> Can use your Signed-off-by for a [cleaned up version of your] patch?

Sure.