Re: [PATCH] iio: bmp280: zero-init buffer

[Jonathan Cameron <jic23@kernel.org>]

On Wed, 07 May 2025 07:24:52 +0100
Nuno Sá <noname.nuno@gmail.com> wrote:

> On Tue, 2025-05-06 at 13:49 -0500, David Lechner wrote:
> > Zero-initialize the buffer used with iio_push_to_buffers_with_ts(). The
> > struct used for the buffer has holes in it, so we need to make sure that
> > the holes are zeroed out rather than containing uninitialized data from
> > the stack.
> > 
> > Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> > Closes: https://lore.kernel.org/linux-iio/aBoBR5D1UMjsSUfZ@stanley.mountain/
> > Fixes: 4e6c3c4801a6 ("iio: pressure: bmp280: drop sensor_data array")
> > Signed-off-by: David Lechner <dlechner@baylibre.com>
> > ---
> > The patch this fixes is currently in iio/togreg, so no need for stable
> > backport, etc.
> > ---  
> 
> Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Applied to the togreg branch of iio.git etc etc.

Thanks
> 
> >  drivers/iio/pressure/bmp280-core.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-
> > core.c
> > index
> > 5728cc18cced223284a2c41dc6dec6f47169c797..f37f20776c89173b0b2a8e28be0ef9aa30ceea53
> > 100644
> > --- a/drivers/iio/pressure/bmp280-core.c
> > +++ b/drivers/iio/pressure/bmp280-core.c
> > @@ -1237,6 +1237,9 @@ static irqreturn_t bme280_trigger_handler(int irq, void *p)
> >  	} buffer;
> >  	int ret;
> >  
> > +	/* Don't leak uninitialized stack to userspace. */
> > +	memset(&buffer, 0, sizeof(buffer));
> > +
> >  	guard(mutex)(&data->lock);
> >  
> >  	/* Burst read data registers */
> > 
> > ---
> > base-commit: 7a175d9667b21b2495913ec7496a6c20aa7a4a89
> > change-id: 20250506-iio-pressure-bmp280-zero-init-buffer-942dd4f48719
> > 
> > Best regards,  
>