============================= WARNING: suspicious RCU usage 4.14.97+ #2 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1590 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 4 locks held by swapper/1/0: #0: (((&net->ipv6.ip6_fib_timer))){+.-.}, at: [] lockdep_copy_map include/linux/lockdep.h:174 [inline] #0: (((&net->ipv6.ip6_fib_timer))){+.-.}, at: [] call_timer_fn+0xc6/0x680 kernel/time/timer.c:1269 #1: (&(&net->ipv6.fib6_gc_lock)->rlock){+.-.}, at: [] spin_lock_bh include/linux/spinlock.h:322 [inline] #1: (&(&net->ipv6.fib6_gc_lock)->rlock){+.-.}, at: [] fib6_run_gc+0x93/0x2a0 net/ipv6/ip6_fib.c:1938 #2: (rcu_read_lock){....}, at: [] __fib6_clean_all+0x0/0x230 net/ipv6/ip6_fib.c:1823 #3: (&tb->tb6_lock){++--}, at: [] __fib6_clean_all+0xde/0x230 net/ipv6/ip6_fib.c:1837 stack backtrace: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.14.97+ #2 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x10e lib/dump_stack.c:53 fib6_del+0x8c2/0xbe0 net/ipv6/ip6_fib.c:1590 fib6_clean_node+0x270/0x440 net/ipv6/ip6_fib.c:1777 fib6_walk_continue+0x3a5/0x5f0 net/ipv6/ip6_fib.c:1703 fib6_walk+0x8d/0xe0 net/ipv6/ip6_fib.c:1748 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:1822 __fib6_clean_all+0xf5/0x230 net/ipv6/ip6_fib.c:1838 fib6_clean_all net/ipv6/ip6_fib.c:1849 [inline] fib6_run_gc+0x104/0x2a0 net/ipv6/ip6_fib.c:1947 call_timer_fn+0x14a/0x680 kernel/time/timer.c:1279 expire_timers+0x216/0x4b0 kernel/time/timer.c:1318 __run_timers kernel/time/timer.c:1634 [inline] run_timer_softirq+0x1eb/0x5d0 kernel/time/timer.c:1647 __do_softirq+0x234/0x9ca kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x114/0x150 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x185/0x620 arch/x86/kernel/apic/apic.c:1064 apic_timer_interrupt+0x84/0x90 arch/x86/entry/entry_64.S:787 RIP: 0010:native_safe_halt+0x2/0x10 arch/x86/include/asm/irqflags.h:58 RSP: 0018:ffff8881daa87d60 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000007 RBX: ffffffffa4830008 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8881daa6b72c RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8881daa6af00 R15: dffffc0000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0x50/0x390 arch/x86/kernel/process.c:564 cpuidle_idle_call kernel/sched/idle.c:159 [inline] do_idle+0x2e6/0x390 kernel/sched/idle.c:268 cpu_startup_entry+0xc6/0xd0 kernel/sched/idle.c:374 start_secondary+0x3a8/0x4b0 arch/x86/kernel/smpboot.c:272 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 mmap: syz-executor3 (5939) uses deprecated remap_file_pages() syscall. See Documentation/vm/remap_file_pages.txt. audit: type=1400 audit(1549354102.952:48): avc: denied { module_load } for pid=5977 comm="syz-executor4" path=2F6D656D66643AEEABB441D76ACFEE7C2AC52CC470726F637468305E202864656C6574656429 dev="tmpfs" ino=16538 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:tmpfs_t:s0 tclass=system permissive=1