lkml.org 
[lkml]   [2018]   [Nov]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PULL] vhost: cleanups and fixes
On Fri, Nov 2, 2018 at 9:59 AM Michael S. Tsirkin <mst@redhat.com> wrote:
>
> Just for completeness I'd like to point out for vhost the copies are
> done from the kernel thread. So yes we can switch to copy_to/from_user
> but for e.g. 32-bit userspace running on top of a 64 bit kernel it is
> IIUC not sufficient - we must *also* do access_ok checks on control path
> when addresses are passed to the kernel and when current points to the
> correct task struct.

Don't you take over the VM with "use_mm()" when you do the copies? So
yes, it's a kernel thread, but it has a user VM, and though that
should have the user limits.

No?

Linus

\
 
 \ /
  Last update: 2018-11-02 18:19    [W:0.071 / U:0.188 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site