lkml.org 
[lkml]   [2016]   [Feb]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] ARM: vdso: Mark vDSO code as read-only
On Tue, Feb 16, 2016 at 01:52:33PM -0800, Kees Cook wrote:
>On Tue, Feb 16, 2016 at 1:36 PM, David Brown <david.brown@linaro.org> wrote:
>> Although the arm vDSO is cleanly separated by code/data with the code
>> being read-only in userspace mappings, the code page is still writable
>> from the kernel. There have been exploits (such as
>> http://itszn.com/blog/?p=21) that take advantage of this on x86 to go
>> from a bad kernel write to full root.
>>
>> Prevent this specific exploit on arm by putting the vDSO code page in
>> post-init read-only memory as well.
>
>Is the vdso dynamically built at init time like on x86, or can this
>just use .rodata directly?

On ARM, it is patched during init. Arm64's is just plain read-only.

David

\
 
 \ /
  Last update: 2016-02-17 06:41    [W:0.113 / U:0.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site