Re: [syzbot] [input?] [usb?] KASAN: slab-use-after-free Read in steam_input_open

[Edward Adam Davis]

#syz test

diff --git a/drivers/hid/hid-steam.c b/drivers/hid/hid-steam.c
index c9e65e9088b3..1d43e4dce14e 100644
--- a/drivers/hid/hid-steam.c
+++ b/drivers/hid/hid-steam.c
@@ -1139,6 +1139,9 @@ static int steam_client_ll_open(struct hid_device *hdev)
 	struct steam_device *steam = hdev->driver_data;
 	unsigned long flags;
 
+	if (!steam->client_hdev)
+		return -ENODEV;
+
 	spin_lock_irqsave(&steam->lock, flags);
 	steam->client_opened++;
 	spin_unlock_irqrestore(&steam->lock, flags);
@@ -1153,11 +1156,12 @@ static void steam_client_ll_close(struct hid_device *hdev)
 	struct steam_device *steam = hdev->driver_data;
 
 	unsigned long flags;
-	bool connected;
+
+	if (!steam->client_hdev)
+		return;
 
 	spin_lock_irqsave(&steam->lock, flags);
 	steam->client_opened--;
-	connected = steam->connected && !steam->client_opened;
 	spin_unlock_irqrestore(&steam->lock, flags);
 
 	schedule_work(&steam->unregister_work);