Re: [PATCH] iio: backend: fix uninitialized data in debugfs

[Andy Shevchenko]

On Tue, Jun 09, 2026 at 09:19:54AM +0300, Dan Carpenter wrote:
> On Fri, Jun 05, 2026 at 11:28:18AM +0300, Andy Shevchenko wrote:
> > On Fri, Jun 05, 2026 at 09:12:38AM +0300, Dan Carpenter wrote:
> > > On Thu, Jun 04, 2026 at 05:55:08PM +0300, Andy Shevchenko wrote:
> > > > On Thu, Jun 04, 2026 at 01:42:11PM +0300, Dan Carpenter wrote:
> > > > > On Thu, Jun 04, 2026 at 01:38:50PM +0300, Dan Carpenter wrote:
> > > > > >    168          ret = sscanf(buf, "%i %i", &back->cached_reg_addr, &val);
> > > > > >                              ^^^
> > > > > > Uninitialized variable.
> > > > > 
> > > > > s/variable/data/.
> > > > 
> > > > With what I asked in the previous reply and what you explained there
> > > > (thanks, btw!) I still think your patches are not fully correct. They
> > > > will require to atomically write all or nothing. If we want support
> > > > partial writes we need to go with that differently (reset ppos when
> > > > we got enough or more than enough data).
> > > 
> > > Requiring writes to syfs and debugfs be atomic is pretty normal and
> > > works well in practice.  These are very small writes.
> > 
> > Perhaps. In any case your patch will break existing partial writes, right?
> 
> partial writes never worked

I don't get this. Does it mean it never worked at all, or in this particular case?
Also "never worked" means the same issue you pointed out (uninitialised buffer) or
something else?

> so this doesn't break anything that wasn't
> already broken.  Another option I considered was just initializing the
> buffer, but returning -EINVAL is the right fix.

-- 
With Best Regards,
Andy Shevchenko