On 3/11/26 10:18 PM, Sabrina Dubroca wrote: > 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.
It looks like even the nipa CI is reproducing the issue, i.e.: https://netdev-ctrl.bots.linux.dev/logs/vmksft/net-dbg/results/554921/17-rtnetlink-sh/ more failures here: https://netdev.bots.linux.dev/contest.html?pw-n=0&branch=net-next-2026-03-12--06-00&pw-n=0&pass=0 the fail in mascsec-offload looks quite deterministic, could you please have a look? /P
