[PATCH 3.16 333/366] HID: reject input outside logical range only if null state is set

[Ben Hutchings]

3.16.61-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Valtteri Heikkilà <rnd@xxxxxx>

commit 3f3752705dbd50b66b66ad7b4d54fe33d2f746ed upstream.

This patch fixes an issue in drivers/hid/hid-input.c where USB HID
control null state flag is not checked upon rejecting inputs outside
logical minimum-maximum range. The check should be made according to USB
HID specification 1.11, section 6.2.2.5, p.31. The fix will resolve
issues with some game controllers, such as:
https://bugzilla.kernel.org/show_bug.cgi?id=68621

[tk@xxxxxxxxxx: shortened and fixed spelling in commit message]
Signed-off-by: Valtteri Heikkilà <rnd@xxxxxx>
Signed-off-by: Tomasz Kramkowski <tk@xxxxxxxxxx>
Acked-By: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/hid/hid-input.c | 1 +
 1 file changed, 1 insertion(+)

--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -1094,6 +1094,7 @@ void hidinput_hid_event(struct hid_devic
 	 * don't specify logical min and max.
 	 */
 	if ((field->flags & HID_MAIN_ITEM_VARIABLE) &&
+	    (field->flags & HID_MAIN_ITEM_NULL_STATE) &&
 	    (field->logical_minimum < field->logical_maximum) &&
 	    (value < field->logical_minimum ||
 	     value > field->logical_maximum)) {