This is a note to let you know that I've just added the patch titled Bluetooth: bfusb: fix division by zero in send path to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: bluetooth-bfusb-fix-division-by-zero-in-send-path.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From b5e6fa7a12572c82f1e7f2f51fbb02a322291291 Mon Sep 17 00:00:00 2001 From: Johan Hovold <johan@xxxxxxxxxx> Date: Mon, 25 Oct 2021 13:39:44 +0200 Subject: Bluetooth: bfusb: fix division by zero in send path From: Johan Hovold <johan@xxxxxxxxxx> 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@xxxxxxxxxxxxxxx Signed-off-by: Johan Hovold <johan@xxxxxxxxxx> Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/bluetooth/bfusb.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/bluetooth/bfusb.c +++ b/drivers/bluetooth/bfusb.c @@ -645,6 +645,9 @@ 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; + rwlock_init(&data->lock); data->reassembly = NULL; Patches currently in stable-queue which might be from johan@xxxxxxxxxx are queue-4.4/bluetooth-bfusb-fix-division-by-zero-in-send-path.patch