lkml.org 
[lkml]   [2018]   [Jul]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RFC PATCH v2 15/27] mm/mprotect: Prevent mprotect from changing shadow stack
From
Date
On 07/10/2018 03:26 PM, Yu-cheng Yu wrote:
> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>

This still needs a changelog, even if you think it's simple.
> --- a/mm/mprotect.c
> +++ b/mm/mprotect.c
> @@ -446,6 +446,15 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
> error = -ENOMEM;
> if (!vma)
> goto out;
> +
> + /*
> + * Do not allow changing shadow stack memory.
> + */
> + if (vma->vm_flags & VM_SHSTK) {
> + error = -EINVAL;
> + goto out;
> + }
> +

I think this is a _bit_ draconian. Why shouldn't we be able to use
protection keys with a shadow stack? Or, set it to PROT_NONE?

\
 
 \ /
  Last update: 2018-07-11 01:11    [W:0.175 / U:1.248 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site