[Libguestfs] [libnbd PATCH v2 5/5] copy: CVE-2022-0485: Fail nbdcopy if NBD read or write fails

[Eric Blake]

On Fri, Feb 04, 2022 at 10:09:26AM +0100, Laszlo Ersek wrote:
> On 02/03/22 21:25, Eric Blake wrote:
> > nbdcopy has a nasty bug when performing multi-threaded copies using
> > asynchronous nbd calls - it was blindly treating the completion of an
> > asynchronous command as successful, rather than checking the *error
> > parameter.  This can result in the silent creation of a corrupted
> > image in two different ways: when a read fails, we blindly wrote
> > garbage to the destination; when a write fails, we did not flag that
> > the destination was not written.
> > 
> > +  /* XXX - is it worth retrying a failed command? */
> > +  if (*error) {
> > +    fprintf (stderr, "read at offset 0x%" PRIx64 "failed: %s\n",
> 
> Like Nir said, it should be '" failed..."'. (I'm neutral on PRIx64 vs.
> PRIu64.)
> 
> Reviewed-by: Laszlo Ersek <lersek at redhat.com>
> 
> Thanks
> Laszlo

Now pushed upstream as a865526..8d444b4, with tweaks to patches 1 and
5 content and patch 4 commit message per review comments.

I'm starting the backport process to stable branches, and will
followup with a top-level post as the security announcement (although
given my schedule today, the announcement may be delayed to Monday).

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org