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authorJonathan Cameron <Jonathan.Cameron@huawei.com>2020-06-07 16:53:57 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-07-22 09:22:22 +0200
commitbb138abda64a0621d42950a997c5ec0075fa7e8f (patch)
treec9232af1dd8ce340395bb3d24d9b9ae5a2ce0095
parent7fd2f25df59c862a3a116003a63e0ac2cb45c5d6 (diff)
iio:pressure:ms5611 Fix buffer element alignment
commit 8db4afe163bbdd93dca6fcefbb831ef12ecc6b4d 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 there is no data leak possibility so use an explicit structure on the stack to ensure alignment and nice readable fashion. The forced alignment of ts isn't strictly necessary in this driver as the padding will be correct anyway (there isn't any). However it is probably less fragile to have it there and it acts as documentation of the requirement. Fixes: 713bbb4efb9dc ("iio: pressure: ms5611: Add triggered buffer support") Reported-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Tomasz Duszynski <tomasz.duszynski@octakon.com> Cc: <Stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/iio/pressure/ms5611_core.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/iio/pressure/ms5611_core.c b/drivers/iio/pressure/ms5611_core.c
index 2a77a2f15752..b4b343c3bd87 100644
--- a/drivers/iio/pressure/ms5611_core.c
+++ b/drivers/iio/pressure/ms5611_core.c
@@ -215,16 +215,21 @@ static irqreturn_t ms5611_trigger_handler(int irq, void *p)
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct ms5611_state *st = iio_priv(indio_dev);
- s32 buf[4]; /* s32 (pressure) + s32 (temp) + 2 * s32 (timestamp) */
+ /* Ensure buffer elements are naturally aligned */
+ struct {
+ s32 channels[2];
+ s64 ts __aligned(8);
+ } scan;
int ret;
mutex_lock(&st->lock);
- ret = ms5611_read_temp_and_pressure(indio_dev, &buf[1], &buf[0]);
+ ret = ms5611_read_temp_and_pressure(indio_dev, &scan.channels[1],
+ &scan.channels[0]);
mutex_unlock(&st->lock);
if (ret < 0)
goto err;
- iio_push_to_buffers_with_timestamp(indio_dev, buf,
+ iio_push_to_buffers_with_timestamp(indio_dev, &scan,
iio_get_time_ns(indio_dev));
err: