Re: [Qemu-devel] [PATCH 0/3] usb-mtp: fix ObjectInfo request handling

[Daniel P . Berrangé]

On Mon, Apr 15, 2019 at 05:54:26PM +0100, Daniel P. Berrangé wrote:
> On Mon, Apr 15, 2019 at 12:52:41PM -0400, Bandan Das wrote:
> > Daniel P. Berrangé <address@hidden> writes:
> > 
> > > Two previous attempts to fix this due to GCC 9 highlighting
> > > unaligned data access. My attempt:
> > >
> > >   https://lists.gnu.org/archive/html/qemu-devel/2019-03/msg07763.html
> > >
> > > And a previous one:
> > >
> > >   https://lists.gnu.org/archive/html/qemu-devel/2019-02/msg07923.html
> > >   https://lists.gnu.org/archive/html/qemu-devel/2019-03/msg00162.html
> > >
> > > There are a number of bugs in the USB MTP usb_mtp_write_metadata
> > > method handling the filename character set conversion.
> > >
> > > The 2nd patch in this series is a security flaw fix since the
> > > code was not correctly validating guest provided data length.
> > >
> > > I've been unable to figure out how to exercise the codepath that
> > > calls usb_mtp_write_metadata. At a guess, it looks like something
> > > that should be called when writing to a file from a guest, but the
> > > GNOME GVFS MTP driver doesn't provide write support. Using the
> > > command line MTP tools "mtp-sendfile" command results in an
> > > protocol error
> > >
> > >     # mtp-sendfile foo eek.txt
> > >     libmtp version: 1.1.14
> > >
> > 
> > The store is read only by default. Are you trying something like:
> >  -device usb-mtp,rootdir=/code/mtpshare,readonly=false ?
> 
> Ah ha, I didn't realize I had to enable write support explicitly. Will
> retry with that.

Even after setting  readonly=false, I still can't get "mtp-sendfile"
to succeed in a guest.

Regards,
Daniel
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