[PATCH 4.10 40/81] HID: wacom: Dont add ghost interface as shared data

[Greg Kroah-Hartman]

4.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Aaron Armstrong Skomra <skomra@xxxxxxxxx>

commit 8b4073596997f2ccbf68d8e72e07b827388a4536 upstream.

A previous commit (below) adds a check for already probed interfaces to
Wacom's matching heuristic. Unfortunately this causes the Bamboo Pen
(CTL-460) to match itself to its 'ghost' touch interface. After
subsequent changes to the driver this match to the ghost causes the
kernel to crash. This patch avoids calling wacom_add_shared_data()
for the BAMBOO_PEN's ghost touch interface.

Fixes: 41372d5d40e7 ("HID: wacom: Augment 'oVid' and 'oPid' with heuristics for HID_GENERIC")
Signed-off-by: Aaron Armstrong Skomra <aaron.skomra@xxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/hid/wacom_sys.c |   16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -2081,6 +2081,14 @@ static int wacom_parse_and_register(stru
 
 	wacom_update_name(wacom, wireless ? " (WL)" : "");
 
+	/* pen only Bamboo neither support touch nor pad */
+	if ((features->type == BAMBOO_PEN) &&
+	    ((features->device_type & WACOM_DEVICETYPE_TOUCH) ||
+	    (features->device_type & WACOM_DEVICETYPE_PAD))) {
+		error = -ENODEV;
+		goto fail;
+	}
+
 	error = wacom_add_shared_data(hdev);
 	if (error)
 		goto fail;
@@ -2127,14 +2135,6 @@ static int wacom_parse_and_register(stru
 		error = -ENODEV;
 		goto fail_quirks;
 	}
-
-	/* pen only Bamboo neither support touch nor pad */
-	if ((features->type == BAMBOO_PEN) &&
-	    ((features->device_type & WACOM_DEVICETYPE_TOUCH) ||
-	    (features->device_type & WACOM_DEVICETYPE_PAD))) {
-		error = -ENODEV;
-		goto fail_quirks;
-	}
 
 	if (features->device_type & WACOM_DEVICETYPE_WL_MONITOR)
 		error = hid_hw_open(hdev);