Kernel bug (vboxdr - VBoxNetFlt) - eth device unintentionally enters promiscuous mode

[petervagyok]

Hello,

When a natnetwork definied. For a while, after some reboots of VM, when VM just started Linux Kernel shows problems. It is reproducabe: make a new natnetwork eg. like this:

$ VBoxManage natnetwork add --netname anyad \
--network "192.168.15.0/24" --enable --ipv6 on \
--port-forward-4 "www:tcp:[]:10080:[192.168.15.10]:80" \
--port-forward-4 "ssh:tcp:[]:10022:[192.168.15.10]:22" \
--port-forward-4 "ssl:tcp:[]:10443:[192.168.15.10]:443" \
--port-forward-6 "www_ipv6:tcp:[]:10080:[192.168.15.10]:80" \
--port-forward-6 "ssh_ipv6:tcp:[]:10022:[192.168.15.10]:22" \
--port-forward-6 "ssl_ipv6:tcp:[]:10443:[192.168.15.10]:443

"

$ VBoxManage dhcpserver modify --ip 192.168.15.3 --netmask 255.255.255.0 \
--netname anyad --lowerip 192.168.15.10 --upperip 192.168.15.100

Then you select natnetwork definied above for VM. After some rebootings of VM there will be Kernel messages just when you start the affected VM like this:

[ 6693.723692] vboxdrv: 0000000000000000 VMMR0.r0
[ 6693.850079] vboxdrv: 0000000000000000 VBoxDDR0.r0
[ 6693.896097] VBoxNetFlt: attached to 'enp3s0' / xx:zz:xx:zz:xx:zz
[ 6693.901656] vboxdrv: 0000000000000000 VBoxEhciR0.r0

No need VM to start the guest OS totally, as soon as VM begun to run the Kernel messages sign. When VM will be just stopped, Kernel message will be like this:

[ 6355.406993] device enp3s0 left promiscuous mode
[ 6356.691870] vboxnetflt: 0 out of 9668 packets were not sent (directed to host)

Temporary workaround:

$ VBoxManage natnetwork remove --netname anyad
$ VBoxManage dhcpserver remove --netname anyad

After re-make a new natnetwork with same option like above I wrote.

Affected VB versions: 6.0.14 and 6.1.0_RC1 r135151

Affected Kernel: Linux 5.0.0-36-generic

[petervagyok]

I forgot: when eth device will be in "promiscuous mode", the natnetwoked VM will be unreachable from any networks and VM won't see any networks too.

[petervagyok]

Also forgot:

After

vboxdrv: 0000000000000000 VBoxEhciR0.r0

line, there is

device enp3s0 entered promiscuous mode

[Socratis]

Do you have a matching VBox.log so that we can cross-reference the events? You were supposed to provide one when you filed the bug. ;)