============================= WARNING: suspicious RCU usage 4.15.0+ #200 Not tainted ----------------------------- ./include/linux/inetdevice.h:216 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by syzkaller616973/4074: #0: (&mm->mmap_sem){++++}, at: [<00000000bfce669e>] __do_page_fault+0x32d/0xc90 arch/x86/mm/fault.c:1355 #1: ((&im->timer)){+.-.}, at: [<00000000619d2f71>] lockdep_copy_map include/linux/lockdep.h:178 [inline] #1: ((&im->timer)){+.-.}, at: [<00000000619d2f71>] call_timer_fn+0x1c6/0x820 kernel/time/timer.c:1316 #2: (&(&im->lock)->rlock){+.-.}, at: [<000000005f833c5c>] spin_lock_bh include/linux/spinlock.h:315 [inline] #2: (&(&im->lock)->rlock){+.-.}, at: [<000000005f833c5c>] igmpv3_send_report+0x98/0x5b0 net/ipv4/igmp.c:600 stack backtrace: CPU: 0 PID: 4074 Comm: syzkaller616973 Not tainted 4.15.0+ #200 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4592 __in_dev_get_rcu include/linux/inetdevice.h:216 [inline] igmpv3_get_srcaddr net/ipv4/igmp.c:329 [inline] igmpv3_newpack+0xeef/0x12e0 net/ipv4/igmp.c:389 add_grhead.isra.27+0x235/0x300 net/ipv4/igmp.c:432 add_grec+0xbd3/0x1170 net/ipv4/igmp.c:565 igmpv3_send_report+0xd5/0x5b0 net/ipv4/igmp.c:605 igmp_send_report+0xc43/0x1050 net/ipv4/igmp.c:722 igmp_timer_expire+0x322/0x5c0 net/ipv4/igmp.c:831 call_timer_fn+0x228/0x820 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers+0x7ee/0xb70 kernel/time/timer.c:1666 run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692 __do_softirq+0x2d7/0xb85 kernel/softirq.c:285 invoke_softirq kernel/softirq.c:365 [inline] irq_exit+0x1cc/0x200 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:541 [inline] smp_apic_timer_interrupt+0x16b/0x700 arch/x86/kernel/apic/apic.c:1052 apic_timer_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:938 RIP: 0010:clear_page_erms+0x7/0x10 arch/x86/lib/clear_page_64.S:49 RSP: 0000:ffff8801c4bcf6b0 EFLAGS: 00010246 ORIG_RAX: ffffffffffffff11 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000240 RDX: ffff8801c11aa300 RSI: 0000160000000000 RDI: ffff8801acd0cdc0 RBP: ffff8801c4bcf700 R08: 000000000002fc10 R09: 0000000000000000 R10: ffffffffffffffe8 R11: 0000000000000000 R12: ffffea0006b30000 R13: 0000000000000012 R14: 0000000000000009 R15: 000000000000010c __do_huge_pmd_anonymous_page mm/huge_memory.c:570 [inline] do_huge_pmd_anonymous_page+0x599/0x1b00 mm/huge_memory.c:728 create_huge_pmd mm/memory.c:3860 [inline] __handle_mm_fault+0x1a0c/0x3ce0 mm/memory.c:4064 handle_mm_fault+0x38f/0x930 mm/memory.c:4130 __do_page_fault+0x5c9/0xc90 arch/x86/mm/fault.c:1426 do_page_fault+0xee/0x720 arch/x86/mm/fault.c:1501 page_fault+0x4c/0x60 arch/x86/entry/entry_64.S:1261 RIP: 0023:0x8048adc RSP: 002b:00000000ff92e370 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00000000ff92e394 RCX: 0000000000000000 RDX: 0000000000000023 RSI: 0000000020209fba RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000286 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000