HID: wacom: Fix error path of power-supply initialization (dde58cfc) · Commits · 戴 / test

power_supply_unregister() must not be called if power_supply_register() failed. The wdata->psy.dev pointer may point to invalid memory after a failed power_supply_register() and hence wacom_remove() will fail while calling power_supply_unregister(). This changes the wacom_probe function to fail if it cannot register the power_supply devices. If we would want to keep the previous behaviour we had to keep some flag about the power_supply state and check it on wacom_remove, but this seems inappropriate here. Hence, we simply fail, too, if power_supply_register fails. Signed-off-by:

David Herrmann <dh.herrmann@googlemail.com> Signed-off-by:

Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-wacom.c

+9 −12

Original line number	Diff line number	Diff line
		@@ -353,11 +353,7 @@ static int wacom_probe(struct hid_device *hdev,
		if (ret) {
		hid_warn(hdev, "can't create sysfs battery attribute, err: %d\n",
		ret);
		/*
		* battery attribute is not critical for the tablet, but if it
		* failed then there is no need to create ac attribute
		*/
		goto move_on;
		goto err_battery;
		}

		wdata->ac.properties = wacom_ac_props;
		@@ -371,14 +367,8 @@ static int wacom_probe(struct hid_device *hdev,
		if (ret) {
		hid_warn(hdev,
		"can't create ac battery attribute, err: %d\n", ret);
		/*
		* ac attribute is not critical for the tablet, but if it
		* failed then we don't want to battery attribute to exist
		*/
		power_supply_unregister(&wdata->battery);
		goto err_ac;
		}

		move_on:
		#endif
		hidinput = list_entry(hdev->inputs.next, struct hid_input, list);
		input = hidinput->input;
		@@ -416,6 +406,13 @@ move_on:

		return 0;

		#ifdef CONFIG_HID_WACOM_POWER_SUPPLY
		err_ac:
		power_supply_unregister(&wdata->battery);
		err_battery:
		device_remove_file(&hdev->dev, &dev_attr_speed);
		hid_hw_stop(hdev);
		#endif
		err_free:
		kfree(wdata);
		return ret;

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