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Commit d472c78c authored by bumwoo lee's avatar bumwoo lee Committed by Greg Kroah-Hartman
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extcon: Modify extcon device to be created after driver data is set 



[ Upstream commit 5dcc2afe716d69f5112ce035cb14f007461ff189 ]

Currently, someone can invoke the sysfs such as state_show()
intermittently before dev_set_drvdata() is done.
And it can be a cause of kernel Oops because of edev is Null at that time.
So modified the driver registration to after setting drviver data.

- Oops's backtrace.

Backtrace:
[<c067865c>] (state_show) from [<c05222e8>] (dev_attr_show)
[<c05222c0>] (dev_attr_show) from [<c02c66e0>] (sysfs_kf_seq_show)
[<c02c6648>] (sysfs_kf_seq_show) from [<c02c496c>] (kernfs_seq_show)
[<c02c4938>] (kernfs_seq_show) from [<c025e2a0>] (seq_read)
[<c025e11c>] (seq_read) from [<c02c50a0>] (kernfs_fop_read)
[<c02c5064>] (kernfs_fop_read) from [<c0231cac>] (__vfs_read)
[<c0231c5c>] (__vfs_read) from [<c0231ee0>] (vfs_read)
[<c0231e34>] (vfs_read) from [<c0232464>] (ksys_read)
[<c02323f0>] (ksys_read) from [<c02324fc>] (sys_read)
[<c02324e4>] (sys_read) from [<c00091d0>] (__sys_trace_return)

Signed-off-by: default avatarbumwoo lee <bw365.lee@samsung.com>
Signed-off-by: default avatarChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent fa0b2dd6

drivers/extcon/extcon.c

+17 −12
Original line number Diff line number Diff line
@@ -1230,19 +1230,14 @@ int extcon_dev_register(struct extcon_dev *edev) 
		edev->dev.type = &edev->extcon_dev_type;

	}



	ret = device_register(&edev->dev);

	if (ret) {

		put_device(&edev->dev);

		goto err_dev;

	}



	spin_lock_init(&edev->lock);

	edev->nh = devm_kcalloc(&edev->dev, edev->max_supported,

				sizeof(*edev->nh), GFP_KERNEL);

	if (edev->max_supported) {

		edev->nh = kcalloc(edev->max_supported, sizeof(*edev->nh),

				GFP_KERNEL);

		if (!edev->nh) {

			ret = -ENOMEM;

		device_unregister(&edev->dev);

		goto err_dev;

			goto err_alloc_nh;

		}

	}



	for (index = 0; index < edev->max_supported; index++)
@@ -1253,6 +1248,12 @@ int extcon_dev_register(struct extcon_dev *edev) 
	dev_set_drvdata(&edev->dev, edev);

	edev->state = 0;



	ret = device_register(&edev->dev);

	if (ret) {

		put_device(&edev->dev);

		goto err_dev;

	}



	mutex_lock(&extcon_dev_list_lock);

	list_add(&edev->entry, &extcon_dev_list);

	mutex_unlock(&extcon_dev_list_lock);
@@ -1260,6 +1261,9 @@ int extcon_dev_register(struct extcon_dev *edev) 
	return 0;



err_dev:

	if (edev->max_supported)

		kfree(edev->nh);

err_alloc_nh:

	if (edev->max_supported)

		kfree(edev->extcon_dev_type.groups);

err_alloc_groups:
@@ -1320,6 +1324,7 @@ void extcon_dev_unregister(struct extcon_dev *edev) 
	if (edev->max_supported) {

		kfree(edev->extcon_dev_type.groups);

		kfree(edev->cables);

		kfree(edev->nh);

	}



	put_device(&edev->dev);