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Subject[PATCH] Bluetooth: fix division by zero in send path
Date
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>
---
drivers/bluetooth/bfusb.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/bluetooth/bfusb.c b/drivers/bluetooth/bfusb.c
index 5a321b4076aa..df80fb324356 100644
--- a/drivers/bluetooth/bfusb.c
+++ b/drivers/bluetooth/bfusb.c
@@ -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
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