[Bug 200210] adding vtnet to bridge results to kernel panic

[Nikos Vassiliadis]

Thank u!

On 07/02/15 00:22, Kristof Provost wrote:
> Done in r285016.
>
> Regards,
> Kristof
>
>> On 01 Jul 2015, at 18:11, Nikos Vassiliadis <nvass at gmx.com> wrote:
>>
>> Hi Kristof,
>>
>> Thanks for fixing this! Could you MFC the fix?
>>
>> On 06/13/15 22:39, bugzilla-noreply at freebsd.org wrote:
>>> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=200210
>>>
>>> --- Comment #1 from commit-hook at freebsd.org ---
>>> A commit references this bug:
>>>
>>> Author: kp
>>> Date: Sat Jun 13 19:39:22 UTC 2015
>>> New revision: 284348
>>> URL: https://svnweb.freebsd.org/changeset/base/284348
>>>
>>> Log:
>>>    Fix panic when adding vtnet interfaces to a bridge
>>>
>>>    vtnet interfaces are always in promiscuous mode (at least if the
>>>    VIRTIO_NET_F_CTRL_RX feature is not negotiated with the host).  if_promisc()
>>> on
>>>    a vtnet interface returned ENOTSUP although it has IFF_PROMISC set. This
>>>    confused the bridge code. Instead we now accept all enable/disable
>>> promiscuous
>>>    commands (and always keep IFF_PROMISC set).
>>>
>>>    There are also two issues with the if_bridge error handling.
>>>
>>>    If if_promisc() fails it uses bridge_delete_member() to clean up. This tries
>>> to
>>>    disable promiscuous mode on the interface. That runs into an assert, because
>>>    promiscuous mode was never set in the first place. (That's the panic reported
>>> in
>>>    PR 200210.)
>>>    We can only unset promiscuous mode if the interface actually is promiscuous.
>>>    This goes against the reference counting done by if_promisc(), but only the
>>>    first/last if_promic() calls can actually fail, so this is safe.
>>>
>>>    A second issue is a double free of bif. It's already freed by
>>>    bridge_delete_member().
>>>
>>>    PR:        200210
>>>    Differential Revision:    https://reviews.freebsd.org/D2804
>>>    Reviewed by:    philip (mentor)
>>>
>>> Changes:
>>>    head/sys/dev/virtio/network/if_vtnet.c
>>>    head/sys/net/if_bridge.c
>>>
>>
>