From: Jonathan Cameron Jonathan.Cameron@huawei.com
commit 2684d5003490df5398aeafe2592ba9d4a4653998 upstream.
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. Here we use a structure on the stack. The driver already did an explicit memset so no data leak was possible.
Forced alignment of ts is not strictly necessary but probably makes the code slightly less fragile.
Note there has been some rework in this driver of the years, so no way this will apply cleanly all the way back.
Fixes: 2690be905123 ("iio: Add Lite-On ltr501 ambient light / proximity sensor driver") Reported-by: Lars-Peter Clausen lars@metafoo.de Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Cc: Stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iio/light/ltr501.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/iio/light/ltr501.c b/drivers/iio/light/ltr501.c index 830a2d45aa4d..947f17588024 100644 --- a/drivers/iio/light/ltr501.c +++ b/drivers/iio/light/ltr501.c @@ -1245,13 +1245,16 @@ static irqreturn_t ltr501_trigger_handler(int irq, void *p) struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct ltr501_data *data = iio_priv(indio_dev); - u16 buf[8]; + struct { + u16 channels[3]; + s64 ts __aligned(8); + } scan; __le16 als_buf[2]; u8 mask = 0; int j = 0; int ret, psdata;
- memset(buf, 0, sizeof(buf)); + memset(&scan, 0, sizeof(scan));
/* figure out which data needs to be ready */ if (test_bit(0, indio_dev->active_scan_mask) || @@ -1270,9 +1273,9 @@ static irqreturn_t ltr501_trigger_handler(int irq, void *p) if (ret < 0) return ret; if (test_bit(0, indio_dev->active_scan_mask)) - buf[j++] = le16_to_cpu(als_buf[1]); + scan.channels[j++] = le16_to_cpu(als_buf[1]); if (test_bit(1, indio_dev->active_scan_mask)) - buf[j++] = le16_to_cpu(als_buf[0]); + scan.channels[j++] = le16_to_cpu(als_buf[0]); }
if (mask & LTR501_STATUS_PS_RDY) { @@ -1280,10 +1283,10 @@ static irqreturn_t ltr501_trigger_handler(int irq, void *p) &psdata, 2); if (ret < 0) goto done; - buf[j++] = psdata & LTR501_PS_DATA_MASK; + scan.channels[j++] = psdata & LTR501_PS_DATA_MASK; }
- iio_push_to_buffers_with_timestamp(indio_dev, buf, + iio_push_to_buffers_with_timestamp(indio_dev, &scan, iio_get_time_ns(indio_dev));
done: