Re: KASAN vs. boot-time switching between 4- and 5-level paging
From: Andrey Ryabinin
Date: Tue Jul 11 2017 - 13:27:58 EST
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?