Bluetooth: hci_sync: Fix not checking error on hci_cmd_sync_cancel_sync

hci_cmd_sync_cancel_sync shall check the error passed to it since it
will be propagated using req_result which is __u32 it needs to be
properly set to a positive value if it was passed as negative othertise
IS_ERR will not trigger as -(errno) would be converted to a positive
value.

Fixes: 63298d6e ("Bluetooth: hci_core: Cancel request on command timeout")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Reported-and-tested-by: Thorsten Leemhuis <linux@leemhuis.info>
Closes: https://lore.kernel.org/all/08275279-7462-4f4a-a0ee-8aa015f829bc@leemhuis.info/

net/bluetooth/hci_core.c

@@ -2874,7 +2874,7 @@ static void hci_cancel_cmd_sync(struct hci_dev *hdev, int err)
 	cancel_delayed_work_sync(&hdev->ncmd_timer);
 	atomic_set(&hdev->cmd_cnt, 1);
 
-	hci_cmd_sync_cancel_sync(hdev, -err);
+	hci_cmd_sync_cancel_sync(hdev, err);
 }
 
 /* Suspend HCI device */
@@ -2894,7 +2894,7 @@ int hci_suspend_dev(struct hci_dev *hdev)
 		return 0;
 
 	/* Cancel potentially blocking sync operation before suspend */
-	hci_cancel_cmd_sync(hdev, -EHOSTDOWN);
+	hci_cancel_cmd_sync(hdev, EHOSTDOWN);
 
 	hci_req_sync_lock(hdev);
 	ret = hci_suspend_sync(hdev);
@@ -4210,7 +4210,7 @@ static void hci_send_cmd_sync(struct hci_dev *hdev, struct sk_buff *skb)
 
 	err = hci_send_frame(hdev, skb);
 	if (err < 0) {
-		hci_cmd_sync_cancel_sync(hdev, err);
+		hci_cmd_sync_cancel_sync(hdev, -err);
 		return;
 	}
 

net/bluetooth/hci_sync.c

@@ -617,7 +617,10 @@ void hci_cmd_sync_cancel_sync(struct hci_dev *hdev, int err)
 	bt_dev_dbg(hdev, "err 0x%2.2x", err);
 
 	if (hdev->req_status == HCI_REQ_PEND) {
-		hdev->req_result = err;
+		/* req_result is __u32 so error must be positive to be properly
+		 * propagated.
+		 */
+		hdev->req_result = err < 0 ? -err : err;
 		hdev->req_status = HCI_REQ_CANCELED;
 
 		wake_up_interruptible(&hdev->req_wait_q);