From b5e6fa7a12572c82f1e7f2f51fbb02a322291291 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 25 Oct 2021 13:39:44 +0200 Subject: [PATCH] Bluetooth: bfusb: 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")). Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold Signed-off-by: Marcel Holtmann --- drivers/bluetooth/bfusb.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/bluetooth/bfusb.c b/drivers/bluetooth/bfusb.c index 5a321b4076aa..cab93935cc7f 100644 --- a/drivers/bluetooth/bfusb.c +++ b/drivers/bluetooth/bfusb.c @@ -628,6 +628,9 @@ 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;