From: Oliver Neukum oneukum@suse.com

mainline inclusion from mainline-v5.15-rc7 commit 397430b50a363d8b7bdda00522123f82df6adc5e category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9RCX9 CVE: CVE-2021-47495

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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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 oneukum@suse.com Reported-by: syzbot+76bb1d34ffa0adc03baa@syzkaller.appspotmail.com Reviewed-by: Johan Hovold johan@kernel.org Link: https://lore.kernel.org/r/20211021122944.21816-1-oneukum@suse.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- 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 7686ebca6d86..695582f3a5cb 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1784,6 +1784,10 @@ 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))