Re: [Qemu-devel] [PATCH 3/3] virtio-blk: Treat read/write beyond end as invalid

[Stefan Hajnoczi]

On Mon, Jun 23, 2014 at 02:57:36PM +0200, Markus Armbruster wrote:
> Markus Armbruster <address@hidden> writes:
> 
> > Stefan Hajnoczi <address@hidden> writes:
> >
> >> On Thu, Jun 05, 2014 at 02:15:36PM +0200, Markus Armbruster wrote:
> >>> +    if (sector > total_sectors || nb_sectors > total_sectors - sector) {
> >>> +        return false;
> >>> +    }
> >>
> >> if (sector >= total_sectors || ...) {
> >
> > I suspect reading bdrv_check_byte_request() put the '>' in my brain:
> >
> >     if ((offset > len) || (len - offset < size))
> >         return -EIO;
> >
> > Don't we need offset >= len here?
> 
> Just remembered: we don't, because we allow I/O at offset len provided
> size is zero.
> 
> Same reasoning applies to my patch.

Okay.  I didn't remember the offset=eof length=0 thing.

Stefan

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