# Re: \[PATCH net\] tun: forbid iface creation with rtnl ops

- From: David Miller \<davem@davemloft.net\>
- Date: 2018-12-01 12:43:25 
- List: netdev
- Page: https://ratatoskr.run/netdev/2018/12/11117031
- Thread: https://ratatoskr.run/netdev/2018/11/11116734/t.md

```text
From: Nicolas Dichtel <redacted>
Date: Thu, 29 Nov 2018 14:45:39 +0100

> It's not supported right now (the goal of the initial patch was to support
> 'ip link del' only).
> 
> Before the patch:
> $ ip link add foo type tun
> [  239.632660] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
> [snip]
> [  239.636410] RIP: 0010:register_netdevice+0x8e/0x3a0
> 
> This panic occurs because dev->netdev_ops is not set by tun_setup(). But to
> have something usable, it will require more than just setting
> netdev_ops.
> 
> Fixes: f019a7a594d9 ("tun: Implement ip link del tunXXX")
> CC: Eric W. Biederman <redacted>
> Signed-off-by: Nicolas Dichtel <redacted>

Super old bug, scary.

Applied, thanks.
```