Re: [PATCH v3 1/3] iio: adc: xilinx-ams: fix out-of-bounds channel lookup in event handling

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 12 May 2026 12:40:05 -0300
Guilherme Ivo Bozi <guilherme.bozi@usp.br> wrote:

> Hi Salih,
> 
> Replies are inline.
> 
> On Tue, May 12, 2026 at 11:22 AM Salih Erim <salih.erim@amd.com> wrote:
> >
> > Hi Guilherme,
> >
> > Replies are inline.
> >
> > On 4/14/2026 11:40 PM, Guilherme Ivo Bozi wrote:  
> > > ams_event_to_channel() may return a pointer past the end of
> > > dev->channels when no matching scan_index is found. This can lead
> > > to invalid memory access in ams_handle_event().
> > >
> > > Add a bounds check in ams_event_to_channel() and return NULL when
> > > no channel is found. Also guard the caller to safely handle this
> > > case.
> > >
> > > Fixes: d5c70627a794 ("iio: adc: Add Xilinx AMS driver")
> > > Signed-off-by: Guilherme Ivo Bozi <guilherme.bozi@usp.br>
> > > ---
> > >   drivers/iio/adc/xilinx-ams.c | 5 +++++
> > >   1 file changed, 5 insertions(+)
> > >
> > > diff --git a/drivers/iio/adc/xilinx-ams.c b/drivers/iio/adc/xilinx-ams.c
> > > index 124470c92529..6191cd1b29a5 100644
> > > --- a/drivers/iio/adc/xilinx-ams.c
> > > +++ b/drivers/iio/adc/xilinx-ams.c
> > > @@ -871,6 +871,9 @@ static const struct iio_chan_spec *ams_event_to_channel(struct iio_dev *dev,
> > >                  if (dev->channels[i].scan_index == scan_index)
> > >                          break;
> > >
> > > +       if (i == dev->num_channels)
> > > +               return NULL;
> > > +  
> > The added lines use spaces for indentation instead of tabs.  
> I checked both locally and the raw mbox from lore.kernel.org, and the
> indentation uses TAB characters consistently (^I in the diff).
> 
> To verify, I inspected the relevant hunk using cat -A:
> 
> ^I^Iif (dev->channels[i].scan_index == scan_index)
> ^I^I^Ibreak;
> 
> +^Iif (i == dev->num_channels)
> +^I^Ireturn NULL;
> 
> ^Ireturn &dev->channels[i];
> 
> I could not observe any indentation issues locally or from the raw mbox.
FWIW they look good to me as well. Salih, I'd guess you have a local issue.
b4 (on git.kernel.org) is really handy for ensuring none of those occur!

Jonathan

> 
> >
> > Salih
> >  
> 
> --
> Guilherme Ivo