Re: [PATCH for 5.10 v2 0/5] vdpa_sim: fix param validation in vdpasim_get_config()

[Stefano Garzarella]

On Wed, Feb 17, 2021 at 11:58:53AM +0100, Greg KH wrote:
> On Tue, Feb 16, 2021 at 03:24:34PM +0100, Stefano Garzarella wrote:
> > v1: https://lore.kernel.org/stable/20210211162519.215418-1-sgarzare@xxxxxxxxxx/
> >
> > v2:
> > - backport the upstream patch and related patches needed
> >
> > Commit 65b709586e22 ("vdpa_sim: add get_config callback in
> > vdpasim_dev_attr") unintentionally solved an issue in vdpasim_get_config()
> > upstream while refactoring vdpa_sim.c to support multiple devices.
> >
> > Before that patch, if 'offset + len' was equal to
> > sizeof(struct virtio_net_config), the entire buffer wasn't filled,
> > returning incorrect values to the caller.
> >
> > Since 'vdpasim->config' type is 'struct virtio_net_config', we can
> > safely copy its content under this condition.
> >
> > The minimum set of patches to backport the patch that fixes the issue, is the
> > following:
> >
> >    423248d60d2b vdpa_sim: remove hard-coded virtq count
> >    6c6e28fe4579 vdpa_sim: add struct vdpasim_dev_attr for device attributes
> >    cf1a3b35382c vdpa_sim: store parsed MAC address in a buffer
> >    f37cbbc65178 vdpa_sim: make 'config' generic and usable for any device type
> >    65b709586e22 vdpa_sim: add get_config callback in vdpasim_dev_attr
> >
> > The patches apply fairly cleanly. There are a few contextual differences
> > due to the lack of the other patches:
> >
> >    $ git backport-diff -u master -r linux-5.10.y..HEAD
>
> Cool, where is 'backport-diff' from?

It was developed by Jeff Cody and I find it very useful when doing or 
reviewing backports :-)

It's available here:
https://github.com/codyprime/git-scripts/blob/master/git-backport-diff

> >    Key:
> >    [----] : patches are identical
> >    [####] : number of functional differences between upstream/downstream patch
> >    [down] : patch is downstream-only
> >    The flags [FC] indicate (F)unctional and (C)ontextual differences, respectively
> >
> >    001/5:[----] [--] 'vdpa_sim: remove hard-coded virtq count'
> >    002/5:[----] [-C] 'vdpa_sim: add struct vdpasim_dev_attr for device attributes'
> >    003/5:[----] [--] 'vdpa_sim: store parsed MAC address in a buffer'
> >    004/5:[----] [-C] 'vdpa_sim: make 'config' generic and usable for any device type'
> >    005/5:[----] [-C] 'vdpa_sim: add get_config callback in vdpasim_dev_attr'
>
> Now all applied, thanks.

Thanks,
Stefano