Hi,

Here are 6 patches that harden console, net and 9p drivers against
various malicious host input as well as close a bounds check bypass
in the split virtio ring.

Changes since previous version:
 * Added Christian's R-B to 3/6
 * Added a speculation fix per Michael's comment on the cover letter
 * CC'ing lkml

Alexander Shishkin (3):
  virtio console: Harden control message handling
  virtio_net: Guard against buffer length overflow in
    xdp_linearize_page()
  virtio_ring: Prevent bounds check bypass on descriptor index

Andi Kleen (3):
  virtio console: Harden multiport against invalid host input
  virtio console: Harden port adding
  virtio 9p: Fix an overflow

 drivers/char/virtio_console.c | 19 ++++++++++++-------
 drivers/net/virtio_net.c      |  4 +++-
 drivers/virtio/virtio_ring.c  |  3 +++
 net/9p/trans_virtio.c         |  2 +-
 4 files changed, 19 insertions(+), 9 deletions(-)

-- 
2.39.0

On Thu, Jan 19, 2023 at 03:57:15PM +0200, Alexander Shishkin wrote:
> Hi,
> 
> Here are 6 patches that harden console, net and 9p drivers against
> various malicious host input as well as close a bounds check bypass
> in the split virtio ring.

Hardening against buggy devices is one thing,
Hardening against malicious devices is another.
Which is this?
If really malicious, aren't there any spectre considerations here?
I am for example surprised not to find anything addressing
spectre v1 nor any uses of array_index_nospec here.


> Changes since previous version:
>  * Added Christian's R-B to 3/6
>  * Added a speculation fix per Michael's comment on the cover letter
>  * CC'ing lkml
> 
> Alexander Shishkin (3):
>   virtio console: Harden control message handling
>   virtio_net: Guard against buffer length overflow in
>     xdp_linearize_page()
>   virtio_ring: Prevent bounds check bypass on descriptor index
> 
> Andi Kleen (3):
>   virtio console: Harden multiport against invalid host input
>   virtio console: Harden port adding
>   virtio 9p: Fix an overflow
> 
>  drivers/char/virtio_console.c | 19 ++++++++++++-------
>  drivers/net/virtio_net.c      |  4 +++-
>  drivers/virtio/virtio_ring.c  |  3 +++
>  net/9p/trans_virtio.c         |  2 +-
>  4 files changed, 19 insertions(+), 9 deletions(-)
> 
> -- 
> 2.39.0

"Michael S. Tsirkin" <mst@redhat.com> writes:

> On Thu, Jan 19, 2023 at 03:57:15PM +0200, Alexander Shishkin wrote:
>> Hi,
>> 
>> Here are 6 patches that harden console, net and 9p drivers against
>> various malicious host input as well as close a bounds check bypass
>> in the split virtio ring.
>
> Hardening against buggy devices is one thing,
> Hardening against malicious devices is another.
> Which is this?

Well, the big difference is the intent, but buggy input is buggy input,
they've got that in common and we're trying to deal with it here.

The motivation for this patchset is protecting against malicious
devices.

> If really malicious, aren't there any spectre considerations here?
> I am for example surprised not to find anything addressing
> spectre v1 nor any uses of array_index_nospec here.

That's strange, patch 6/6 is exactly that. There's probably more coming
in the future as the analysis and audit progress.

Regards,
--
Alex

On Fri, Jan 20, 2023 at 02:32:09PM +0200, Alexander Shishkin wrote:
> "Michael S. Tsirkin" <mst@redhat.com> writes:
> 
> > On Thu, Jan 19, 2023 at 03:57:15PM +0200, Alexander Shishkin wrote:
> >> Hi,
> >> 
> >> Here are 6 patches that harden console, net and 9p drivers against
> >> various malicious host input as well as close a bounds check bypass
> >> in the split virtio ring.
> >
> > Hardening against buggy devices is one thing,
> > Hardening against malicious devices is another.
> > Which is this?
> 
> Well, the big difference is the intent, but buggy input is buggy input,
> they've got that in common and we're trying to deal with it here.
> 
> The motivation for this patchset is protecting against malicious
> devices.
> 
> > If really malicious, aren't there any spectre considerations here?
> > I am for example surprised not to find anything addressing
> > spectre v1 nor any uses of array_index_nospec here.
> 
> That's strange, patch 6/6 is exactly that. There's probably more coming
> in the future as the analysis and audit progress.
> 
> Regards,

Oh I see, didn't get it for some reason. Pulled it from lore now.

> --
> Alex