Re: [LKP] [x86/KASLR] ed9f007ee6: -- System halted

[Baoquan He]

On 06/30/16 at 05:24pm, Yinghai Lu wrote:
> On Wed, Jun 29, 2016 at 11:58 PM, Ye Xiaolong <xiaolong.ye@xxxxxxxxx> wrote:
> > On Wed, Jun 29, 2016 at 09:49:12PM -0700, Yinghai Lu wrote:
> >>On Wed, Jun 29, 2016 at 1:29 PM, Huang, Ying <ying.huang@xxxxxxxxx> wrote:
> >>> If you could provide a git branch for that, that will be easier for us
> >>> to test and more accurate for you to get the right patch to be tested.
> >>>
> >>
> >>Please check
> >>
> >>git://git.kernel.org/pub/scm/linux/kernel/git/yinghai/linux-yinghai.git
> >>for-x86-v4.8-kaslr-debug
> >
> > Hi, yinghai
> >
> > Attached is the dmesg for the kernel which is built based on your
> > for-x86-v4.8-kaslr-debug branch.
> 
> Thanks for capturing the boot log.
> 
> early console in setup code
> early console in extract_kernel
> decompress_kernel:
>        input: [0x0008fba276-0x000a8818ed]
>       output: [0x0001000000-0x000a867c97] 0x09867c98: output_len
>               [0x0001000000-0x0009768fff] 0x08769000: run_size
>               [0x0001000000-0x000a867c97] 0x09867c98: output_run_size
>               [0x0001000000-0x000a8affff] 0x098b0000: init_size
> ZO text/data: [0x000a8818ee-0x000a8affff]
>      ZO heap: [0x000a888400-0x000a8983ff]
>   VO bss/brk: [0x0009674000-0x0009768fff]
> booted via startup_32()
> Physical KASLR using RDTSC...
> Virtual KASLR using RDTSC...
>   new output: [0x0006600000-0x000fe67c97] 0x09867c98: output_run_size
>    virt_addr:  0x0024000000
>   decompress: [0x0006600000-0x000fe67c97] <=== [0x0008fba276-0x000a8818ed]
> 
> Decompressing Linux...
> 
> XZ-compressed data is corrupt
> 
>  -- System halted
> 
> Hi Kees/Baoquan,
> 
> Looks like
> 
> commit ed9f007ee68478f6a50ec9971ade25a0129a5c0e
> Author: Kees Cook <keescook@xxxxxxxxxxxx>
> Date:   Wed May 25 15:45:33 2016 -0700
> 
>     x86/KASLR: Extend kernel image physical address randomization to addresses l
> arger than 4G

I know why it happened, making patch. will reply soon.

> 
> 
> cause choose_random_location() return new output buffer
> new output: [0x0006600000-0x000fe67c97] 0x09867c98: output_run_size
> 
> that is overlapped with input data.
>        input: [0x0008fba276-0x000a8818ed]
>               ....-0x000a8affff] 0x098b0000: init_size
> 
> and input already is in mem_avoid.