[PATCH] staging: vchiq: silence an uninitialized variable warning

[Dan Carpenter]

On Wed, Sep 30, 2020 at 12:22:37PM +0200, Arnd Bergmann wrote:
> On Wed, Sep 30, 2020 at 11:02 AM Dan Carpenter <dan.carpenter at oracle.com> wrote:
> >
> > Smatch complains that "userdata" can be passed to vchiq_bulk_transfer()
> > without being initialized.  Smatch is correct, however, in that
> > situation the "userdata" is not used so it doesn't cause a problem.
> > Passing an uninitialized variable will trigger a UBSan warning at
> > runtime so this warning is worth silencing by setting "userdata" to
> > NULL.
> >
> > Fixes: a4367cd2b231 ("staging: vchiq: convert compat bulk transfer")
> > Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
> 
> The change looks fine, but I wonder if it's actually worse and the
> uninitialized pointer can end up getting copied back to user space
> in the completion.

Ah... Wow.  You're right.  I think I really need to resend this with a
more accurate commit message.

regards,
dan carpenter