>From a5270791d4480e9a6bc009c69a4454039aa160e7 Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Tue, 19 Oct 2021 10:02:42 +0200 Subject: [PATCH] usbnet: sanity check for maxpacket We cannot leave maxpacket at 0 because we divide by it. Devices that give us a 0 there are unlikely to work, but let's assume a 1, so we don't oops and a least try to operate. Signed-off-by: Oliver Neukum Reported-by: syzbot+76bb1d34ffa0adc03baa@syzkaller.appspotmail.com --- drivers/net/usb/usbnet.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 840c1c2ab16a..2bdc3e0c1579 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1788,6 +1788,9 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod) if (!dev->rx_urb_size) dev->rx_urb_size = dev->hard_mtu; dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1); + if (dev->maxpacket == 0) + /* that is a strange device */ + dev->maxpacket = 1; /* let userspace know we have a random address */ if (ether_addr_equal(net->dev_addr, node_id)) -- 2.26.2