Re: [PATCH net] vhost: validate log when IOTLB is enabled

From: David Miller
Date: Thu Mar 29 2018 - 16:23:20 EST


From: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
Date: Thu, 29 Mar 2018 15:48:22 +0300

> On Thu, Mar 29, 2018 at 04:00:04PM +0800, Jason Wang wrote:
>> Vq log_base is the userspace address of bitmap which has nothing to do
>> with IOTLB. So it needs to be validated unconditionally otherwise we
>> may try use 0 as log_base which may lead to pin pages that will lead
>> unexpected result (e.g trigger BUG_ON() in set_bit_to_user()).
>>
>> Fixes: 6b1e6cc7855b0 ("vhost: new device IOTLB API")
>> Reported-by: syzbot+6304bf97ef436580fede@xxxxxxxxxxxxxxxxxxxxxxxxx
>> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
>
> Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
>
> stable material I guess.

Applied and queued up for -stable.