From: Jonathan Cameron <jic23@kernel.org>
To: Tomasz Duszynski <tomasz.duszynski@octakon.com>
Cc: <linux-iio@vger.kernel.org>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Lars-Peter Clausen <lars@metafoo.de>,
Tomasz Duszynski <tduszyns@gmail.com>
Subject: Re: [PATCH 11/11] iio:chemical:pms7003: Fix timestamp alignment and prevent data leak.
Date: Thu, 21 May 2020 19:44:04 +0100 [thread overview]
Message-ID: <20200521194404.2102a3ff@archlinux> (raw)
In-Reply-To: <20200517190655.GA18033@arch>
On Sun, 17 May 2020 21:06:55 +0200
Tomasz Duszynski <tomasz.duszynski@octakon.com> wrote:
> On Sun, May 17, 2020 at 06:30:00PM +0100, jic23@kernel.org wrote:
> > From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> >
> > One of a class of bugs pointed out by Lars in a recent review.
> > iio_push_to_buffers_with_timestamp assumes the buffer used is aligned
> > to the size of the timestamp (8 bytes). This is not guaranteed in
> > this driver which uses an array of smaller elements on the stack.
> > As Lars also noted this anti pattern can involve a leak of data to
> > userspace and that indeed can happen here. We close both issues by
> > moving to a suitable structure in the iio_priv() data with alignment
> > explicitly requested. This data is allocated with kzalloc so no
> > data can leak appart from previous readings.
> >
> > Fixes: a1d642266c14 ("iio: chemical: add support for Plantower PMS7003 sensor")
> > Reported-by: Lars-Peter Clausen <lars@metafoo.de>
> > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > Cc: Tomasz Duszynski <tduszyns@gmail.com>
> > ---
> > drivers/iio/chemical/pms7003.c | 17 ++++++++++++-----
> > 1 file changed, 12 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/iio/chemical/pms7003.c b/drivers/iio/chemical/pms7003.c
> > index 23c9ab252470..07bb90d72434 100644
> > --- a/drivers/iio/chemical/pms7003.c
> > +++ b/drivers/iio/chemical/pms7003.c
> > @@ -73,6 +73,11 @@ struct pms7003_state {
> > struct pms7003_frame frame;
> > struct completion frame_ready;
> > struct mutex lock; /* must be held whenever state gets touched */
> > + /* Used to construct scan to push to the IIO buffer */
> > + struct {
> > + u16 data[3]; /* PM1, PM2P5, PM10 */
> > + s64 ts;
> > + } scan;
> > };
> >
> > static int pms7003_do_cmd(struct pms7003_state *state, enum pms7003_cmd cmd)
> > @@ -104,7 +109,6 @@ static irqreturn_t pms7003_trigger_handler(int irq, void *p)
> > struct iio_dev *indio_dev = pf->indio_dev;
> > struct pms7003_state *state = iio_priv(indio_dev);
> > struct pms7003_frame *frame = &state->frame;
> > - u16 data[3 + 1 + 4]; /* PM1, PM2P5, PM10, padding, timestamp */
> > int ret;
> >
> > mutex_lock(&state->lock);
> > @@ -114,12 +118,15 @@ static irqreturn_t pms7003_trigger_handler(int irq, void *p)
> > goto err;
> > }
> >
> > - data[PM1] = pms7003_get_pm(frame->data + PMS7003_PM1_OFFSET);
> > - data[PM2P5] = pms7003_get_pm(frame->data + PMS7003_PM2P5_OFFSET);
> > - data[PM10] = pms7003_get_pm(frame->data + PMS7003_PM10_OFFSET);
> > + state->scan.data[PM1] =
> > + pms7003_get_pm(frame->data + PMS7003_PM1_OFFSET);
> > + state->scan.data[PM2P5] =
> > + pms7003_get_pm(frame->data + PMS7003_PM2P5_OFFSET);
> > + state->scan.data[PM10] =
> > + pms7003_get_pm(frame->data + PMS7003_PM10_OFFSET);
> > mutex_unlock(&state->lock);
> >
> > - iio_push_to_buffers_with_timestamp(indio_dev, data,
> > + iio_push_to_buffers_with_timestamp(indio_dev, &state->scan,
> > iio_get_time_ns(indio_dev));
> > err:
> > iio_trigger_notify_done(indio_dev->trig);
> > --
> > 2.26.2
> >
>
> Thanks for the fix.
> Acked-by: Tomasz Duszynski <tomasz.duszynski@octakon.com>
>
Applied. Thanks,
prev parent reply other threads:[~2020-05-21 18:44 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-17 17:29 [PATCH 00/11] IIO: 1st set of timestamp alignment fixes jic23
2020-05-17 17:29 ` [PATCH 01/11] iio: accel: kxsd9: Fix alignment of local buffer jic23
2020-05-17 17:29 ` [PATCH 02/11] iio:accel:mma8452: Fix timestamp alignment and prevent data leak jic23
2020-05-17 18:57 ` Lars-Peter Clausen
2020-05-18 16:37 ` Jonathan Cameron
2020-05-17 17:29 ` [PATCH 03/11] iio:accel:bmc150-accel: " jic23
2020-05-17 17:29 ` [PATCH 04/11] iio:accel:mma7455: " jic23
2020-05-17 17:29 ` [PATCH 05/11] iio:gyro:itg3200: " jic23
2020-05-17 17:29 ` [PATCH 06/11] iio:proximity:mb1232: " jic23
2020-05-17 17:29 ` [PATCH 07/11] iio:health:afe4403 " jic23
2020-05-18 0:09 ` Andrew F. Davis
2020-05-18 16:06 ` Jonathan Cameron
2020-05-21 13:11 ` Andrew F. Davis
2020-05-21 14:44 ` Jonathan Cameron
2020-05-21 18:45 ` Jonathan Cameron
2020-05-21 19:05 ` Andrew F. Davis
2020-05-24 15:33 ` Jonathan Cameron
2020-05-17 17:29 ` [PATCH 08/11] iio:health:afe4404 " jic23
2020-05-24 15:34 ` Jonathan Cameron
2020-05-17 17:29 ` [PATCH 09/11] iio:chemical:ccs811: " jic23
2020-05-17 17:29 ` [PATCH 10/11] iio:chemical:sps30: Fix timestamp alignment jic23
2020-05-17 19:07 ` Tomasz Duszynski
2020-05-21 18:43 ` Jonathan Cameron
2020-05-17 17:30 ` [PATCH 11/11] iio:chemical:pms7003: Fix timestamp alignment and prevent data leak jic23
2020-05-17 19:06 ` Tomasz Duszynski
2020-05-21 18:44 ` Jonathan Cameron [this message]
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