syzbot has bisected this bug to: commit 58956317c8de52009d1a38a721474c24aef74fe7 Author: David Ahern <dsahern@xxxxxxxxx> Date: Fri Dec 7 20:24:57 2018 +0000 neighbor: Improve garbage collection bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1328a1e2e00000 start commit: addb0679 Merge git://git.kernel.org/pub/scm/linux/kernel/g.. git tree: net-next final crash: https://syzkaller.appspot.com/x/report.txt?x=10a8a1e2e00000 console output: https://syzkaller.appspot.com/x/log.txt?x=1728a1e2e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=d9655b05acfc97ff dashboard link: https://syzkaller.appspot.com/bug?extid=6a3c02010a025ac7b7cf syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13317705400000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=177bb01b400000 Reported-by: syzbot+6a3c02010a025ac7b7cf@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 58956317c8de ("neighbor: Improve garbage collection") For information about bisection process see: https://goo.gl/tpsmEJ#bisection