From 524f333e98138d909a0a0c574a9ff6737dce2767 Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Thu, 21 Oct 2021 14:29:44 +0200 Subject: [PATCH] usbnet: sanity check for maxpacket commit 397430b50a363d8b7bdda00522123f82df6adc5e upstream. maxpacket of 0 makes no sense and oopses as we need to divide by it. Give up. V2: fixed typo in log and stylistic issues Signed-off-by: Oliver Neukum Reported-by: syzbot+76bb1d34ffa0adc03baa@syzkaller.appspotmail.com Reviewed-by: Johan Hovold Link: https://lore.kernel.org/r/20211021122944.21816-1-oneukum@suse.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/usb/usbnet.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 0b5fd1499ac0..965e1a7b179f 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1740,6 +1740,10 @@ 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 broken device */ + goto out4; + } /* let userspace know we have a random address */ if (ether_addr_equal(net->dev_addr, node_id)) -- 2.20.1