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Subject[PATCH 4.19 001/239] Bluetooth: bfusb: fix division by zero in send path
From: Johan Hovold <>

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")).

Signed-off-by: Johan Hovold <>
Signed-off-by: Marcel Holtmann <>
Signed-off-by: Greg Kroah-Hartman <>
drivers/bluetooth/bfusb.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/bluetooth/bfusb.c
+++ b/drivers/bluetooth/bfusb.c
@@ -644,6 +644,9 @@ static int bfusb_probe(struct usb_interf
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;

data->reassembly = NULL;

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