IPVS: Creating netns size=2536 id=7
IPVS: Creating netns size=2536 id=8

===============================
[ INFO: suspicious RCU usage. ]
4.9.79-g71f1469 #25 Not tainted
-------------------------------
./include/linux/inetdevice.h:205 suspicious rcu_dereference_check() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 0
2 locks held by syz-executor0/6565:
 #0:  (((&im->timer))){+.-...}, at: [<ffffffff812a56c4>] lockdep_copy_map include/linux/lockdep.h:165 [inline]
 #0:  (((&im->timer))){+.-...}, at: [<ffffffff812a56c4>] call_timer_fn+0xe4/0x700 kernel/time/timer.c:1309
 #1:  (&(&im->lock)->rlock){+.-...}, at: [<ffffffff832fbe39>] spin_lock_bh include/linux/spinlock.h:307 [inline]
 #1:  (&(&im->lock)->rlock){+.-...}, at: [<ffffffff832fbe39>] igmpv3_send_report+0x39/0x480 net/ipv4/igmp.c:600

stack backtrace:
CPU: 0 PID: 6565 Comm: syz-executor0 Not tainted 4.9.79-g71f1469 #25
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801db207968 ffffffff81d94829 ffff8801d3ad6000 0000000000000000
 0000000000000002 ffffffff83f2fe60 00000000160000e0 ffff8801db207998
 ffffffff81238379 ffff8801d8348c80 ffff8801b19a4410 ffff8801bd575680
Call Trace:
 <IRQ> [   35.926978]  [<ffffffff81d94829>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ> [   35.926978]  [<ffffffff81d94829>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81238379>] lockdep_rcu_suspicious+0x139/0x180 kernel/locking/lockdep.c:4455
 [<ffffffff832f66dc>] __in_dev_get_rcu include/linux/inetdevice.h:205 [inline]
 [<ffffffff832f66dc>] igmpv3_get_srcaddr net/ipv4/igmp.c:329 [inline]
 [<ffffffff832f66dc>] igmpv3_newpack+0xc3c/0xe80 net/ipv4/igmp.c:389
 [<ffffffff832f6b55>] add_grhead.isra.29+0x235/0x300 net/ipv4/igmp.c:432
 [<ffffffff832f79c2>] add_grec+0xae2/0x1010 net/ipv4/igmp.c:565
 [<ffffffff832fbe7f>] igmpv3_send_report+0x7f/0x480 net/ipv4/igmp.c:605
 [<ffffffff832fcc87>] igmp_send_report+0x997/0xc90 net/ipv4/igmp.c:722
 [<ffffffff832fd7ad>] igmp_timer_expire+0x29d/0x3d0 net/ipv4/igmp.c:831
 [<ffffffff812a5744>] call_timer_fn+0x164/0x700 kernel/time/timer.c:1319
 [<ffffffff812a79cc>] expire_timers kernel/time/timer.c:1359 [inline]
 [<ffffffff812a79cc>] __run_timers kernel/time/timer.c:1658 [inline]
 [<ffffffff812a79cc>] run_timer_softirq+0xe8c/0x1650 kernel/time/timer.c:1684
 [<ffffffff838ba0c6>] __do_softirq+0x206/0x951 kernel/softirq.c:284
 [<ffffffff81146be5>] invoke_softirq kernel/softirq.c:364 [inline]
 [<ffffffff81146be5>] irq_exit+0x165/0x190 kernel/softirq.c:405
 [<ffffffff838b8cdb>] exiting_irq arch/x86/include/asm/apic.h:659 [inline]
 [<ffffffff838b8cdb>] smp_apic_timer_interrupt+0x7b/0xa0 arch/x86/kernel/apic/apic.c:960
 [<ffffffff838b4f60>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:752
 <EOI> [   36.130660]  [<ffffffff82ed49f0>] ? sock_release+0x1e0/0x1e0 net/socket.c:608
 [<ffffffff815759f5>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff811957c5>] task_work_run+0x115/0x190 kernel/task_work.c:116
 [<ffffffff8113c267>] exit_task_work include/linux/task_work.h:21 [inline]
 [<ffffffff8113c267>] do_exit+0x7e7/0x2a40 kernel/exit.c:833
 [<ffffffff81142978>] do_group_exit+0x108/0x320 kernel/exit.c:937
 [<ffffffff811657d4>] get_signal+0x4d4/0x14e0 kernel/signal.c:2317
 [<ffffffff81052c87>] do_signal+0x87/0x1a00 arch/x86/kernel/signal.c:807
 [<ffffffff81003a31>] exit_to_usermode_loop+0xe1/0x120 arch/x86/entry/common.c:156
 [<ffffffff81006340>] prepare_exit_to_usermode arch/x86/entry/common.c:190 [inline]
 [<ffffffff81006340>] syscall_return_slowpath+0x1a0/0x1e0 arch/x86/entry/common.c:259
 [<ffffffff838b352b>] entry_SYSCALL_64_fastpath+0xe6/0xe8