Bluetooth: fix division by zero in send path

Add the missing bulk-out endpoint sanity check to probe() to avoid division by zero in bfusb_send_frame() in case a malicious device has broken descriptors (or when doing descriptor fuzz testing).

Note that USB core will reject URBs submitted for endpoints with zero wMaxPacketSize but that drivers doing packet-size calculations still need to handle this (cf. commit 2548288b4fb0 ("USB: Fix: Don't skip endpoint descriptors with maxpacket=0")).

---
 drivers/bluetooth/bfusb.c | 2 ++
 1 file changed, 2 insertions(+)

index 5a321b4076aa..df80fb324356 100644
@@ -627,6 +627,8 @@ static int bfusb_probe(struct usb_interface *intf, const struct usb_device_id *i
 	data->bulk_in_ep    = bulk_in_ep->desc.bEndpointAddress;
 	data->bulk_out_ep   = bulk_out_ep->desc.bEndpointAddress;
 	data->bulk_pkt_size = le16_to_cpu(bulk_out_ep->desc.wMaxPacketSize);
+	if (!data->bulk_pkt_size)
+		goto done;
 
 	rwlock_init(&data->lock);
 

2.32.0

Hi Johan,

patch has been applied to bluetooth-next tree.

Regards

Marcel