lkml.org 
[lkml]   [2016]   [Feb]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCHv2] lkdtm: Add READ_AFTER_FREE test
From
Date
On 02/23/2016 02:37 PM, Kees Cook wrote:
> On Tue, Feb 23, 2016 at 1:25 PM, Kees Cook <keescook@chromium.org> wrote:
>
>> zero poison only:
>> DEBUG_PAGEALLOC=n
>> PAGE_POISONING=y
>> PAGE_POISONING_NO_SANITY=y
>> PAGE_POISONING_ZERO=y
>> page_poison=on
>
> This combo (in next-20160223) results in an unusable system. :(
>
> [ 1.754183] random: init urandom read with 11 bits of entropy available
> [ 1.768449] hostname (1171) used greatest stack depth: 11808 bytes left
> [ 1.787954] BUG: Bad page map in process init pte:3d656c6f736e6f63
> pmd:00020067
> [ 1.789177] addr:00007f9f68200000 vm_flags:00000070 anon_vma:
> (null) mapping:ffff88007c314058 index:141
> [ 1.790564] file:libdl-2.19.so fault:ext4_filemap_fault
> mmap:ext4_file_mmap readpage:ext4_readpage
>
> -Kees
>

Hmmm, it looks like the -mm tree currently only has the v1 of the
poisoning patches and not the v2. The v1 had a bug which would
cause issues like this due to some pages not getting zeroed fully. I should
follow up on that today.

Thanks,
Laura

\
 
 \ /
  Last update: 2016-02-24 20:41    [W:0.083 / U:0.364 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site