Bug 706036 – sys-kernel/gentoo-sources-4.19.97: IPv6 on macvlan regression

• Status: RESOLVED FIXED
• Product: Gentoo Linux

[Description Constantin Baranov 2020-01-21 21:07:46 UTC]

Created attachment 603920 [details]
emerge --info

Problem does not appear on previous stable kernel, 4.9.86. Kernel config is the same. System is exactly the same. I booted both kernels back and forth a few times, 100% repro.

I use systemd-networkd. Here is all its configs:

/etc/systemd/network $ cat enp0s31f6.network 
[Match]
Name=enp0s31f6

[Network]
DHCP=no
IPv6AcceptRA=false
MACVLAN=macvlan0
/etc/systemd/network $ cat macvlan0.netdev 
[NetDev]
Name=macvlan0
Kind=macvlan

[MACVLAN]
Mode=bridge
/etc/systemd/network $ cat macvlan0.network 
[Match]
Name=macvlan0

[Link]
#MACAddress=

[Network]
BindCarrier=enp0s31f6
DHCP=ipv4
IPv6PrivacyExtensions=true
IPv6AcceptRA=true
MulticastDNS=true

[DHCP]
UseMTU=true
UseDomains=true

enp0s31f6 is connected to ISP router that announces IPv6 /64 subnet.

[Comment 1 Constantin Baranov 2020-01-21 21:08:39 UTC]

Created attachment 603922 [details]
config-4.9.97-gentoo

[Comment 2 Constantin Baranov 2020-01-22 01:42:08 UTC]

I should have clarified: the actual symptom is that IPv6 addresses are never assigned to macvlan0 interface. IPv4 continues to work via DHCP.

[Comment 3 Michael Jones 2020-01-25 09:12:07 UTC]

I think it's a bit worse than that.

My macvlan interfaces aren't responding to ARP at all.

I found this reddit conversation: https://www.reddit.com/r/archlinux/comments/er6yg0/macvlan_arp_and_lts_kernels_41994/

And this patch (from the linked reddit conversation) https://bugzilla.kernel.org/show_bug.cgi?id=206223

I use macvlan very heavily, so this kernel is a significant regression for me.

Can the kernel be revbumped and have the provided patch backported?

[Comment 4 Constantin Baranov 2020-01-25 10:08:23 UTC]

Indeed, I confirm that the patch 1712b2fff8c682d145c7889d2290696647d82dab helps.

[Comment 5 Mike Pagano 2020-01-25 16:00:16 UTC]

(In reply to Constantin Baranov from comment #4)
> Indeed, I confirm that the patch 1712b2fff8c682d145c7889d2290696647d82dab
> helps.

Hi,

Just to confirm, you applied and tested the patch against the 4.19 series.
Is that correct?

[Comment 6 Constantin Baranov 2020-01-27 02:30:06 UTC]

(In reply to Mike Pagano from comment #5)
> (In reply to Constantin Baranov from comment #4)
> > Indeed, I confirm that the patch 1712b2fff8c682d145c7889d2290696647d82dab
> > helps.
> 
> Hi,
> 
> Just to confirm, you applied and tested the patch against the 4.19 series.
> Is that correct?

I applied it to sys-kernel/gentoo-sources-4.19.97.

[Comment 7 Mike Pagano 2020-01-29 13:09:53 UTC]

(In reply to Constantin Baranov from comment #6)
> (In reply to Mike Pagano from comment #5)
> > (In reply to Constantin Baranov from comment #4)
> > > Indeed, I confirm that the patch 1712b2fff8c682d145c7889d2290696647d82dab
> > > helps.
> > 
> > Hi,
> > 
> > Just to confirm, you applied and tested the patch against the 4.19 series.
> > Is that correct?
> 
> I applied it to sys-kernel/gentoo-sources-4.19.97.

The patch made it into 4.19.98.  Can you test 4.19.99, please?

[Comment 8 Constantin Baranov 2020-01-29 23:51:10 UTC]

(In reply to Mike Pagano from comment #7)
> The patch made it into 4.19.98.  Can you test 4.19.99, please?

4.19.99 works for me.

[Comment 9 Mike Pagano 2020-01-29 23:57:36 UTC]

Thanks for testing