patch "iio:accel:bma180: rearrange iio trigger get and register" added to char-misc-linus

patch "iio:accel:bma180: rearrange iio trigger get and register" added to char-misc-linus

[gregkh]

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

    iio:accel:bma180: rearrange iio trigger get and register

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 e5f3205b04d7f95a2ef43bce4b454a7f264d6923 Mon Sep 17 00:00:00 2001
From: Dmitry Rokosov <DDRokosov@sberdevices.ru>
Date: Tue, 24 May 2022 18:14:39 +0000
Subject: iio:accel:bma180: rearrange iio trigger get and register

IIO trigger interface function iio_trigger_get() should be called after
iio_trigger_register() (or its devm analogue) strictly, because of
iio_trigger_get() acquires module refcnt based on the trigger->owner
pointer, which is initialized inside iio_trigger_register() to
THIS_MODULE.
If this call order is wrong, the next iio_trigger_put() (from sysfs
callback or "delete module" path) will dereference "default" module
refcnt, which is incorrect behaviour.

Fixes: 0668a4e4d297 ("iio: accel: bma180: Fix indio_dev->trig assignment")
Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220524181150.9240-2-ddrokosov@sberdevices.ru
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/iio/accel/bma180.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c
index 4f73bc827eec..9c9e98578667 100644
--- a/drivers/iio/accel/bma180.c
+++ b/drivers/iio/accel/bma180.c
@@ -1006,11 +1006,12 @@ static int bma180_probe(struct i2c_client *client,
 
 		data->trig->ops = &bma180_trigger_ops;
 		iio_trigger_set_drvdata(data->trig, indio_dev);
-		indio_dev->trig = iio_trigger_get(data->trig);
 
 		ret = iio_trigger_register(data->trig);
 		if (ret)
 			goto err_trigger_free;
+
+		indio_dev->trig = iio_trigger_get(data->trig);
 	}
 
 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
-- 
2.36.1