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

[Kirill A. Shutemov]

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?


-- 
 Kirill A. Shutemov