Re: [PATCH 2/2] usb: typec: tipd: Add an additional overflow check

[Greg Kroah-Hartman]

On Tue, Sep 14, 2021 at 01:18:16PM +0200, Sven Peter wrote:
> 
> 
> On Tue, Sep 14, 2021, at 13:00, Greg Kroah-Hartman wrote:
> > On Tue, Sep 14, 2021 at 12:42:53PM +0200, Sven Peter wrote:
> > > tps6598x_block_read already checks for the maximum length of the read
> > > but tps6598x_block_write does not. Add the symmetric check there as
> > > well.
> > > 
> > > Signed-off-by: Sven Peter <sven@xxxxxxxxxxxxx>
> > > ---
> > >  drivers/usb/typec/tipd/core.c | 3 +++
> > >  1 file changed, 3 insertions(+)
> > > 
> > > diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
> > > index c18ec3785592..70e2d0d410c9 100644
> > > --- a/drivers/usb/typec/tipd/core.c
> > > +++ b/drivers/usb/typec/tipd/core.c
> > > @@ -139,6 +139,9 @@ static int tps6598x_block_write(struct tps6598x *tps, u8 reg,
> > >  {
> > >  	u8 data[TPS_MAX_LEN + 1];
> > >  
> > > +	if (WARN_ON(len + 1 > sizeof(data)))
> > > +		return -EINVAL;
> > 
> > No need to crash anything.  If this is a valid thing for us to check,
> > let's check it and handle the error, but we should not reboot systems
> > that are running with panic-on-warn enabled, right?
> 
> Sure, that makes sense. I guess the same point applies to the WARN_ON in
> the same check in tps6598x_block_read. I can add a patch to remove that one
> to v2 as well.

That would be great, thanks.

greg k-h