patch "iio: core: Fix entry not deleted when iio_register_sw_trigger_type()" added to char-misc-linus

patch "iio: core: Fix entry not deleted when iio_register_sw_trigger_type()" added to char-misc-linus

[gregkh]

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

    iio: core: Fix entry not deleted when iio_register_sw_trigger_type()

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 4ad09d956f8eacff61e67e5b13ba8ebec3232f76 Mon Sep 17 00:00:00 2001
From: Chen Zhongjin <chenzhongjin@huawei.com>
Date: Tue, 8 Nov 2022 11:28:02 +0800
Subject: iio: core: Fix entry not deleted when iio_register_sw_trigger_type()
 fails

In iio_register_sw_trigger_type(), configfs_register_default_group() is
possible to fail, but the entry add to iio_trigger_types_list is not
deleted.

This leaves wild in iio_trigger_types_list, which can cause page fault
when module is loading again. So fix this by list_del(&t->list) in error
path.

BUG: unable to handle page fault for address: fffffbfff81d7400
Call Trace:
<TASK>
 iio_register_sw_trigger_type
 do_one_initcall
 do_init_module
 load_module
 ...

Fixes: b662f809d410 ("iio: core: Introduce IIO software triggers")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Link: https://lore.kernel.org/r/20221108032802.168623-1-chenzhongjin@huawei.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/iio/industrialio-sw-trigger.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/industrialio-sw-trigger.c b/drivers/iio/industrialio-sw-trigger.c
index 994f03a71520..d86a3305d9e8 100644
--- a/drivers/iio/industrialio-sw-trigger.c
+++ b/drivers/iio/industrialio-sw-trigger.c
@@ -58,8 +58,12 @@ int iio_register_sw_trigger_type(struct iio_sw_trigger_type *t)
 
 	t->group = configfs_register_default_group(iio_triggers_group, t->name,
 						&iio_trigger_type_group_type);
-	if (IS_ERR(t->group))
+	if (IS_ERR(t->group)) {
+		mutex_lock(&iio_trigger_types_lock);
+		list_del(&t->list);
+		mutex_unlock(&iio_trigger_types_lock);
 		ret = PTR_ERR(t->group);
+	}
 
 	return ret;
 }
-- 
2.38.1