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

Lee Jones lee at kernel.org
Thu Sep 8 23:59:49 PDT 2022


On Thu, 08 Sep 2022, Dan Carpenter wrote:

> 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.

Dropped.

-- 
Lee Jones [李琼斯]



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