[PATCH 3.16 66/72] HID: hiddev: do cleanup in failure of opening a device

[Ben Hutchings]

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

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

From: Hillf Danton <hdanton@xxxxxxxx>

commit 6d4472d7bec39917b54e4e80245784ea5d60ce49 upstream.

Undo what we did for opening before releasing the memory slice.

Reported-by: syzbot <syzbot+62a1e04fd3ec2abf099e@xxxxxxxxxxxxxxxxxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Signed-off-by: Hillf Danton <hdanton@xxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/hid/usbhid/hiddev.c | 4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/hid/usbhid/hiddev.c
+++ b/drivers/hid/usbhid/hiddev.c
@@ -322,6 +322,10 @@ static int hiddev_open(struct inode *ino
 	return 0;
 bail_unlock:
 	mutex_unlock(&hiddev->existancelock);
+
+	spin_lock_irq(&list->hiddev->list_lock);
+	list_del(&list->node);
+	spin_unlock_irq(&list->hiddev->list_lock);
 bail:
 	file->private_data = NULL;
 	vfree(list);