Re: WARNING in dln2_start_rx_urbs/usb_submit_urb

[Lee Jones <lee.jones@linaro.org>]

On Wed, 20 Nov 2019, Oliver Neukum wrote:

> #syz test: https://github.com/google/kasan.git b1aa9d83
> 
> From 6f3de1e2c53fcee54d90a6891df9cea763eca86b Mon Sep 17 00:00:00 2001
> From: Oliver Neukum <oneukum@suse.com>
> Date: Wed, 20 Nov 2019 16:15:13 +0100
> Subject: [PATCH] mfd: dln2: more sanity checking for endpoints
> 
> It is not enough to check for the number of endpoints.
> The types must also be correct.
> 
> Reported-by: syzbot+48a2851be24583b864dc@syzkaller.appspotmail.com
> Signed-off-by: Oliver Neukum <oneukum@suse.com>
> ---
>  drivers/mfd/dln2.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)

Looks okay in principle.

It would be great if one of the USB guys could take a quick look.

Is this not something that could be done at a subsystem level?

> diff --git a/drivers/mfd/dln2.c b/drivers/mfd/dln2.c
> index 381593fbe50f..7841c11411d0 100644
> --- a/drivers/mfd/dln2.c
> +++ b/drivers/mfd/dln2.c
> @@ -722,6 +722,8 @@ static int dln2_probe(struct usb_interface *interface,
>  		      const struct usb_device_id *usb_id)
>  {
>  	struct usb_host_interface *hostif = interface->cur_altsetting;
> +	struct usb_endpoint_descriptor *epin;
> +	struct usb_endpoint_descriptor *epout;
>  	struct device *dev = &interface->dev;
>  	struct dln2_dev *dln2;
>  	int ret;
> @@ -731,12 +733,19 @@ static int dln2_probe(struct usb_interface *interface,
>  	    hostif->desc.bNumEndpoints < 2)
>  		return -ENODEV;
>  
> +	epin = &hostif->endpoint[0].desc;
> +	epout = &hostif->endpoint[1].desc;
> +	if (!usb_endpoint_is_bulk_out(epout))
> +		return -ENODEV;
> +	if (!usb_endpoint_is_bulk_in(epin))
> +		return -ENODEV;
> +
>  	dln2 = kzalloc(sizeof(*dln2), GFP_KERNEL);
>  	if (!dln2)
>  		return -ENOMEM;
>  
> -	dln2->ep_out = hostif->endpoint[0].desc.bEndpointAddress;
> -	dln2->ep_in = hostif->endpoint[1].desc.bEndpointAddress;
> +	dln2->ep_out = epout->bEndpointAddress;
> +	dln2->ep_in = epin->bEndpointAddress;
>  	dln2->usb_dev = usb_get_dev(interface_to_usbdev(interface));
>  	dln2->interface = interface;
>  	usb_set_intfdata(interface, dln2);

-- 
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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