Commit ed5c2683 authored Oct 25, 2021 by Johan Hovold Committed by Greg Kroah-Hartman Jan 16, 2022

Bluetooth: bfusb: fix division by zero in send path



commit b5e6fa7a12572c82f1e7f2f51fbb02a322291291 upstream.

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")).

Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 784e873a

drivers/bluetooth/bfusb.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -629,6 +629,9 @@ static int bfusb_probe(struct usb_interface intf, const struct usb_device_id i
		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);

		data->reassembly = NULL;