Re: kernel crash making a vlan on a wlan

On Sun, Apr 24, 2022, 8:30 AM Rob Wing <rob.fx907@gmail.com> wrote:

> What do you mean when you say they are the same thing?
>

There is no semantic difference between the two notations. The change will
have no effect.

Warner

On Sun, Apr 24, 2022 at 5:35 AM Warner Losh <imp@bsdimp.com> wrote:
>
>>
>>
>> On Sun, Apr 24, 2022, 1:03 AM Rob Wing <rob.fx907@gmail.com> wrote:
>>
>>> From what I can tell, the vlan driver is calling ieee80211_output() with
>>> the wrong ifnet context and dereferencing a bad pointer.
>>>
>>> It looks like the passed in if_softc is pointing to a struct ifvlan
>>> instead of the expected struct ieee80211_vap
>>>
>>> Looking at vlan_output(), I wonder if the parents ifnet context should
>>> be used when calling if_output()? something like:
>>>
>>> diff --git a/sys/net/if_vlan.c b/sys/net/if_vlan.c
>>> index 2bb5284c2129..5fbd7a79dccc 100644
>>> --- a/sys/net/if_vlan.c
>>> +++ b/sys/net/if_vlan.c
>>> @@ -1318,7 +1318,7 @@ vlan_output(struct ifnet *ifp, struct mbuf *m,
>>> const struct sockaddr *dst,
>>>                 ifv = p->if_softc;
>>>         } while (p->if_type == IFT_L2VLAN);
>>>
>>> -       return p->if_output(ifp, m, dst, ro);
>>> +       return ((*p->if_output)(p, m, dst, ro));
>>>
>>
>> No. Those two are the same thing.
>>
>> Warner
>>
>>  }
>>>
>>>  #ifdef ALTQ
>>>
>>>
>>> On Sat, Apr 23, 2022 at 1:12 PM Eugene Grosbein <eugen@grosbein.net>
>>> wrote:
>>>
>>>> 24.04.2022 3:28, Marek Zarychta wrote:
>>>>
>>>> > W dniu 23.04.2022 o 22:11, Craig Leres pisze:
>>>> >>
>>>> >> On 4/23/22 11:12, Craig Leres wrote:
>>>> >>> I am able to reproduce the crash with 13.1-RC4.
>>>> >>
>>>> >> I'm also able to reproduce the crash on 12.3-RELEASE-p5. It seems
>>>> wlan0 is part of the recipe, I tried vlans_em0="vlan0" first but was not
>>>> able to induce a crash.
>>>> >>
>>>> >>          Craig
>>>> >>
>>>> >
>>>> > I am curious what is this WiFi hardware that supports 802.1q tagging
>>>> over the air? Could you please reveal this?
>>>> >
>>>> > That's rather not a bug when you are shooting yourself in the foot.
>>>>
>>>> Kernel panic due to ifconfig command is always a bug.
>>>>
>>>>
>>>>
>>>>