[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 1/5] virtio-pci: ignore unaligned read/write in
From: |
Gerd Hoffmann |
Subject: |
Re: [Qemu-devel] [PATCH 1/5] virtio-pci: ignore unaligned read/write in virtio_address_space_read()/write() |
Date: |
Mon, 13 Jul 2015 09:53:43 +0200 |
On Mo, 2015-07-13 at 10:36 +0300, Michael S. Tsirkin wrote:
> On Mon, Jul 13, 2015 at 01:46:47PM +0800, Jason Wang wrote:
> > We abort on unaligned read/write in
> > virtio_address_space_read()/write() but since len in under control of
> > guest so qemu will simply crash when booting a modern guest (guest is
> > try to read when len is zero).
> > read.
>
> How can len be 0? Isn't this a guest bug? Or is this
> a theoretical issue?
Something dumping pci config space?
With pci access capability not being used before and therefore zeroed?
Then hitting the "data" field will trigger a zero-length read.
That assert actually triggers when booting a recent linux kernel with
disable-modern=off
cheers,
Gerd
- Re: [Qemu-devel] [PATCH 4/5] Revert "virtio-net: enable virtio 1.0", (continued)
Re: [Qemu-devel] [PATCH 1/5] virtio-pci: ignore unaligned read/write in virtio_address_space_read()/write(), Michael S. Tsirkin, 2015/07/13
- Re: [Qemu-devel] [PATCH 1/5] virtio-pci: ignore unaligned read/write in virtio_address_space_read()/write(),
Gerd Hoffmann <=
Re: [Qemu-devel] [PATCH 1/5] virtio-pci: ignore unaligned read/write in virtio_address_space_read()/write(), Jason Wang, 2015/07/13