linux-kernel - Re: [PATCH v5] virtio-blk: Add validation for block size in config space

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 5 Oct 2021 23:24:04 +0800
From:   Yongji Xie <xieyongji@...edance.com>
To:     "Michael S. Tsirkin" <mst@...hat.com>
Cc:     Jason Wang <jasowang@...hat.com>,
        Stefan Hajnoczi <stefanha@...hat.com>,
        virtualization <virtualization@...ts.linux-foundation.org>,
        linux-block@...r.kernel.org,
        linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v5] virtio-blk: Add validation for block size in config space

On Mon, Oct 4, 2021 at 11:27 PM Michael S. Tsirkin <mst@...hat.com> wrote:
>
> On Mon, Aug 09, 2021 at 06:16:09PM +0800, Xie Yongji wrote:
> > An untrusted device might presents an invalid block size
> > in configuration space. This tries to add validation for it
> > in the validate callback and clear the VIRTIO_BLK_F_BLK_SIZE
> > feature bit if the value is out of the supported range.
> >
> > And we also double check the value in virtblk_probe() in
> > case that it's changed after the validation.
> >
> > Signed-off-by: Xie Yongji <xieyongji@...edance.com>
>
> So I had to revert this due basically bugs in QEMU.
>
> My suggestion at this point is to try and update
> blk_queue_logical_block_size to BUG_ON when the size
> is out of a reasonable range.
>
> This has the advantage of fixing more hardware, not just virtio.
>

I wonder if it's better to just add a new patch to remove the
virtblk_validate() part. And the check of block size in
virtblk_probe() can be safely removed after the block layer is changed
to validate the block size.

Thanks,
Yongji