[PATCH] mfd: mt6370: add bounds checking to regmap_read/write functions

[Dan Carpenter]

On Thu, Sep 08, 2022 at 07:57:16AM +0100, Lee Jones wrote:
> On Mon, 22 Aug 2022, Dan Carpenter wrote:
> 
> > On Fri, Aug 19, 2022 at 09:27:13AM +0300, Andy Shevchenko wrote:
> > > On Fri, Aug 19, 2022 at 8:25 AM Dan Carpenter <dan.carpenter at oracle.com> wrote:
> > > >
> > > > It looks like there are a potential out of bounds accesses in the
> > > > read/write() functions.  Also can "len" be negative?  Let's check for
> > > > that too.
> > > 
> > > ...
> > > 
> > > > Fixes: ab9905c5e38e ("mfd: mt6370: Add MediaTek MT6370 support")
> > > 
> > > > From static analysis.  This code is obviously harmless however it may
> > > > not be required.  The regmap range checking is slightly complicated and
> > > > I haven't remembered where all it's done.
> > > 
> > > Exactement! I do not think this Fixes anything, I believe you are
> > > adding a dead code. So, can you do deeper analysis?
> > 
> > I spent a long time looking at this code before I sent it and I've
> > spent a long time looking at it today.
> > 
> > Smatch said that these values come from the user, but now it seems
> > less clear to me and I have rebuilt the DB so I don't have the same
> > information I was looking at earlier.
> > 
> > So I can't see if these come from the user but neither can I find any
> > bounds checking.
> 
> What's the consensus please?

Let's drop it.  I think it's not required.

regards,
dan carpenter