Hello BIRDs! And hello Ondřej. As a part of my thesis I've been toying with EVPN in BIRD on the oz-evpn branch and I managed to run into a segfault when I add ethernet interface into a bridge. I am using a couple fedora 42 VMs and I have this running in pnetlab but I hope virtualization is not a problem here. I narrowed it down to this very minimal bird.conf: ``` log stderr all; log "/var/log/bird.log" all; router id 10.10.10.3; ipv4 table master4; protocol device { scan time 10; }``` and a reproducer is basically what is in the README in [cf-evpn-bgp-tags](https://gitlab.nic.cz/labs/bird-tools/-/tree/master/netlab/cf-evpn-bgp-tags) test: ``` [root@debug ~]# ip link add name br0 type bridge vlan_filtering 1 [root@debug ~]# ip link add name vxlan0 type vxlan id 100 local 10.10.10.3 dstport 4789 nolearning [root@debug ~]# ip link set vxlan0 master br0[root@debug ~]# bridge link set dev vxlan0 learning off [root@debug ~]# ip link set dev eth1 master br0 [root@debug ~]# bird -fSegmentation fault (core dumped) ``` I spent some time debugging this, although I am not too familiar with netlink I hope my description will be useful :) Segfault happens in "sysdep/linux/netlink.c" because [this strcmp](https://gitlab.nic.cz/labs/bird/-/blob/oz-evpn/sysdep/linux/netlink.c?ref_ty...) on line 1037 gets a NULL in the first parameter "kind" which seems expected based on that "kind" is set conditionally. Looking at the [array li](https://gitlab.nic.cz/labs/bird/-/blob/oz-evpn/sysdep/linux/netlink.c?ref_ty...) and its size == 3 and into the "nl_parse_attrs" function I understand that you are only trying to get the first three (?) IFLA_INFO_x items which are IFLA_INFO_UNSPEC, IFLA_INFO_KIND, IFLA_INFO_DATA. The first "a->rta_type" that I see on my eth1 interface has a value 4 which is the IFLA_INFO_SLAVE_KIND and reading the data from it I indeed get "bridge" as a result. All of these get skipped by the first [continue](https://gitlab.nic.cz/labs/bird/-/blob/oz-evpn/sysdep/linux/netlink.c?ref_ty...) so "nl_parse_attrs" does not return anything useful. Is it possible that netlink is just not sending the data you need? Bug most likely comes from [66edbe43](https://gitlab.nic.cz/labs/bird/-/commit/66edbe43ce1fec8465577637c359d0294f5...) commit which is specific to the oz-evpn branch so other non-evpn branches are unaffected. I'm also attaching a patch which fixes it for me and I can have EVPN up and running. Thank you for your time and I hope you'll have a great day! Tomáš