patch "iio:humidity:hts221: rearrange iio trigger get and register" added to char-misc-linus

[<gregkh@linuxfoundation.org>]

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

    iio:humidity:hts221: 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 10b9c2c33ac706face458feab8965f11743c98c0 Mon Sep 17 00:00:00 2001
From: Dmitry Rokosov <DDRokosov@sberdevices.ru>
Date: Tue, 24 May 2022 18:14:46 +0000
Subject: iio:humidity:hts221: 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: e4a70e3e7d84 ("iio: humidity: add support to hts221 rh/temp combo device")
Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220524181150.9240-6-ddrokosov@sberdevices.ru
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/iio/humidity/hts221_buffer.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/humidity/hts221_buffer.c b/drivers/iio/humidity/hts221_buffer.c
index f29692b9d2db..66b32413cf5e 100644
--- a/drivers/iio/humidity/hts221_buffer.c
+++ b/drivers/iio/humidity/hts221_buffer.c
@@ -135,9 +135,12 @@ int hts221_allocate_trigger(struct iio_dev *iio_dev)
 
 	iio_trigger_set_drvdata(hw->trig, iio_dev);
 	hw->trig->ops = &hts221_trigger_ops;
+
+	err = devm_iio_trigger_register(hw->dev, hw->trig);
+
 	iio_dev->trig = iio_trigger_get(hw->trig);
 
-	return devm_iio_trigger_register(hw->dev, hw->trig);
+	return err;
 }
 
 static int hts221_buffer_preenable(struct iio_dev *iio_dev)
-- 
2.36.1