[PATCH 5.5 028/367] mfd: dln2: More sanity checking for endpoints

Greg Kroah-Hartman
2020-02-10T12:51:56Z

From: Oliver Neukum <oneukum@suse.com>

commit 2b8bd606b1e60ca28c765f69c1eedd7d2a2e9dca upstream.

It is not enough to check for the number of endpoints.
The types must also be correct.

Reported-and-tested-by: syzbot+48a2851be24583b864dc@syzkaller.appspotmail.com
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/mfd/dln2.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

--- a/drivers/mfd/dln2.c
+++ b/drivers/mfd/dln2.c
@@ -722,6 +722,8 @@ static int dln2_probe(struct usb_interfa
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_interfa
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);