From: Johan Hovold <johan@kernel.org>
Date: Mon, 25 Oct 2021 11:39:44 +0000 (+0200)
Subject: Bluetooth: bfusb: fix division by zero in send path
X-Git-Tag: v6.1-rc5~2306^2~428^2~51
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b5e6fa7a12572c82f1e7f2f51fbb02a322291291;p=platform%2Fkernel%2Flinux-starfive.git

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 <johan@kernel.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
---

diff --git a/drivers/bluetooth/bfusb.c b/drivers/bluetooth/bfusb.c
index 5a321b4..cab9393 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;