# \[PATCHv2\] usbnet: sanity check for maxpacket

- Subsystems: NETWORKING DRIVERS, USB "USBNET" DRIVER FRAMEWORK, THE REST, USB NETWORKING DRIVERS
- Maintainers: Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Oliver Neukum, Linus Torvalds
- Status: LANDED (397430b50a36 · 2021-10-21 13:44)
- Landed in mainline as 397430b50a36 on 2021-10-21.
- List: netdev
- 3 messages, 3 authors
- Page: https://ratatoskr.run/netdev/2021/10/8879206/t

## \[PATCHv2\] usbnet: sanity check for maxpacket

- From: Oliver Neukum \<oneukum@suse.com\>
- Date: 2021-10-21 12:29:50 
- Message: https://ratatoskr.run/netdev/2021/10/8879206.md

```text
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: <redacted>
---
 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 840c1c2ab16a..80432ee0ce69 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1788,6 +1788,10 @@ 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))
-- 
2.26.2

```

## Re: \[PATCHv2\] usbnet: sanity check for maxpacket

- From: Johan Hovold \<johan@kernel.org\>
- Date: 2021-10-21 12:38:32 
- Message: https://ratatoskr.run/netdev/2021/10/8879207.md

```text
On Thu, Oct 21, 2021 at 02:29:44PM +0200, Oliver Neukum wrote:
> 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

Changelog goes below the ---

> Signed-off-by: Oliver Neukum <oneukum@suse.com>
> Reported-by: <redacted>

Again,

Reviewed-by: Johan Hovold <johan@kernel.org>

> ---
>  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 840c1c2ab16a..80432ee0ce69 100644
> --- a/drivers/net/usb/usbnet.c
> +++ b/drivers/net/usb/usbnet.c
> @@ -1788,6 +1788,10 @@ 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))
```

## Re: \[PATCHv2\] usbnet: sanity check for maxpacket

- From: patchwork-bot+netdevbpf@kernel.org
- Date: 2021-10-21 15:10:10 
- Message: https://ratatoskr.run/netdev/2021/10/8879212.md

```text
Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski [ref]:

On Thu, 21 Oct 2021 14:29:44 +0200 you wrote:
> 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: <redacted>
> 
> [...]

Here is the summary with links:
  - [PATCHv2] usbnet: sanity check for maxpacket
    https://git.kernel.org/netdev/net/c/397430b50a36

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html


```