2026-03-11, 00:47:41 +0000, Hangbin Liu wrote: > On Tue, Mar 10, 2026 at 08:17:01PM +0100, Sabrina Dubroca wrote: > > 2026-03-10, 10:02:09 -0700, syzbot ci wrote: > > > batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): > > > interface not active > > > hsr_slave_0: entered promiscuous mode > > > hsr_slave_1: entered promiscuous mode > > > ------------[ cut here ]------------ > > > err == -EMSGSIZE > > > WARNING: net/core/rtnetlink.c:4421 at rtmsg_ifinfo_build_skb+0x218/0x260, > > > CPU#0: syz-executor/6496 > > > > I'm not sure this one is caused by this series, but either way, > > > rtnetlink_event+0x1b7/0x270 > notifier_call_chain+0x1be/0x400 > netdev_change_features+0x95/0xe0 > __netdev_upper_dev_link+0xb20/0xc80 > netdev_upper_dev_link+0xb0/0x100 > > > This patch calls netdev_change_features() after __netdev_upper_dev_link(), > Which trigger a NETDEV_FEAT_CHANGE notify and calls rtmsg_ifinfo_event() > to fill the new link info. Maybe the event is a bit early and macsec has > data not ready?
But this would still mean that there's a mismatch between if_nlmsg_size() and rtnl_fill_ifinfo(), and your patch is only revealing it. I'll send fixes for the stuff I mentioned, no idea if that's what syzbot saw since we don't have a repro. -- Sabrina
