This is a note to let you know that I've just added the patch titled

iio: mma8452: Fix trigger reference couting

to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From cd0082235783f814241a1c9483fb89e405f4f892 Mon Sep 17 00:00:00 2001

From: Lars-Peter Clausen lars@metafoo.de Date: Sun, 24 Oct 2021 11:26:59 +0200 Subject: iio: mma8452: Fix trigger reference couting

The mma8452 driver directly assigns a trigger to the struct iio_dev. The IIO core when done using this trigger will call `iio_trigger_put()` to drop the reference count by 1.

Without the matching `iio_trigger_get()` in the driver the reference count can reach 0 too early, the trigger gets freed while still in use and a use-after-free occurs.

Fix this by getting a reference to the trigger before assigning it to the IIO device.

Fixes: ae6d9ce05691 ("iio: mma8452: Add support for interrupt driven triggers.") Signed-off-by: Lars-Peter Clausen lars@metafoo.de Link: https://lore.kernel.org/r/20211024092700.6844-1-lars@metafoo.de Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com --- drivers/iio/accel/mma8452.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c index 715b8138fb71..09c7f10fefb6 100644 --- a/drivers/iio/accel/mma8452.c +++ b/drivers/iio/accel/mma8452.c @@ -1470,7 +1470,7 @@ static int mma8452_trigger_setup(struct iio_dev *indio_dev) if (ret) return ret;

- indio_dev->trig = trig; + indio_dev->trig = iio_trigger_get(trig);

return 0; }