# Re: \[RFC PATCH v3 12/24\] x86/mm: Modify ptep\_set\_wrprotect and pmdp\_set\_wrprotect for \_PAGE\_DIRTY\_SW

- From: Dave Hansen \<dave.hansen@linux.intel.com\>
- Date: 2018-08-30 17:36:18 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2018/08/5367906
- Thread: https://ratatoskr.run/linux-doc/2018/08/5367691/t.md

```text
On 08/30/2018 10:26 AM, Yu-cheng Yu wrote:
> We don't have the guard page now, but there is a shadow stack token
> there, which cannot be used as a return address.

The overall concern is that we could overflow into a page that we did
not intend.  Either another actual shadow stack or something that a page
that the attacker constructed, like the transient scenario Jann described.
```