syzbot has bisected this issue 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=12d31675900000
start commit: 12450081 libbpf: Fix native endian assumption when parsing..
git tree: bpf
final oops: https://syzkaller.appspot.com/x/report.txt?x=11d31675900000
console output: https://syzkaller.appspot.com/x/log.txt?x=16d31675900000
kernel config: https://syzkaller.appspot.com/x/.config?x=5ac0d21536db480b
dashboard link: https://syzkaller.appspot.com/bug?extid=cc36fd07553c0512f5f7
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1365d2c3900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16d5f08d900000
Reported-by: syzbot+cc36fd07553c0512f5f7@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 58956317c8de ("neighbor: Improve garbage collection")
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
