Merge branch 'for-5.4/hidraw-hiddev-epoll' into for-linus

[platform/kernel/linux-rpi.git] / drivers / hid / usbhid / hiddev.c

diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c
index 73a76d9..1f9bc44 100644 (file)
--- a/drivers/hid/usbhid/hiddev.c
+++ b/drivers/hid/usbhid/hiddev.c
@@ -284,6 +284,14 @@ static int hiddev_open(struct inode *inode, struct file *file)
        spin_unlock_irq(&list->hiddev->list_lock);
 
        mutex_lock(&hiddev->existancelock);
+       /*
+        * recheck exist with existance lock held to
+        * avoid opening a disconnected device
+        */
+       if (!list->hiddev->exist) {
+               res = -ENODEV;
+               goto bail_unlock;
+       }
        if (!list->hiddev->open++)
                if (list->hiddev->exist) {
                        struct hid_device *hid = hiddev->hid;
@@ -300,6 +308,10 @@ bail_normal_power:
        hid_hw_power(hid, PM_HINT_NORMAL);
 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);