===============================
[ INFO: suspicious RCU usage. ]
4.4.172+ #13 Not tainted
-------------------------------
net/ipv6/ip6_fib.c:1465 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:


rcu_scheduler_active = 1, debug_locks = 0
6 locks held by syz-executor3/2138:
 #0:  (tasklist_lock){.+.+..}, at: [<ffffffff810de53e>] do_wait+0x2be/0xa00 kernel/exit.c:1507
 #1:  (rcu_read_lock){......}, at: [<ffffffff8195607c>] avc_has_perm_noaudit security/selinux/avc.c:1106 [inline]
 #1:  (rcu_read_lock){......}, at: [<ffffffff8195607c>] avc_has_perm+0xac/0x3a0 security/selinux/avc.c:1146
 #2:  (((&net->ipv6.ip6_fib_timer))){+.-...}, at: [<ffffffff8125801e>] lockdep_copy_map include/linux/lockdep.h:165 [inline]
 #2:  (((&net->ipv6.ip6_fib_timer))){+.-...}, at: [<ffffffff8125801e>] call_timer_fn+0xde/0x850 kernel/time/timer.c:1175
 #3:  (fib6_gc_lock){+.-...}, at: [<ffffffff825f99ea>] spin_lock_bh include/linux/spinlock.h:307 [inline]
 #3:  (fib6_gc_lock){+.-...}, at: [<ffffffff825f99ea>] fib6_run_gc+0x3a/0x230 net/ipv6/ip6_fib.c:1811
 #4:  (rcu_read_lock){......}, at: [<ffffffff825f1590>] __fib6_clean_all+0x0/0x240 net/ipv6/ip6_fib.c:1698
 #5:  (&tb->tb6_lock){++--..}, at: [<ffffffff825f1678>] __fib6_clean_all+0xe8/0x240 net/ipv6/ip6_fib.c:1712

stack backtrace:
CPU: 0 PID: 2138 Comm: syz-executor3 Not tainted 4.4.172+ #13
 0000000000000000 8785af0b37a47a87 ffff8801db607940 ffffffff81aacde1
 ffff8800a13af6c0 0000000000000000 0000000000000001 00000000000005b9
 ffff8800bb4397c0 ffff8801db607970 ffffffff813ab5d0 ffff8801db607b90
Call Trace:
 <IRQ>  [<ffffffff81aacde1>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ>  [<ffffffff81aacde1>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<ffffffff813ab5d0>] lockdep_rcu_suspicious.cold+0x10a/0x149 kernel/locking/lockdep.c:4305
 [<ffffffff825f918a>] fib6_del+0x7ea/0xae0 net/ipv6/ip6_fib.c:1465
 [<ffffffff825f971c>] fib6_clean_node+0x29c/0x500 net/ipv6/ip6_fib.c:1652
 [<ffffffff825f0ee0>] fib6_walk_continue+0x3e0/0x630 net/ipv6/ip6_fib.c:1578
 [<ffffffff825f1421>] fib6_walk+0x91/0xe0 net/ipv6/ip6_fib.c:1623
 [<ffffffff825f1558>] fib6_clean_tree+0xe8/0x120 net/ipv6/ip6_fib.c:1697
 [<ffffffff825f1690>] __fib6_clean_all+0x100/0x240 net/ipv6/ip6_fib.c:1713
 [<ffffffff825f9a5f>] fib6_clean_all net/ipv6/ip6_fib.c:1724 [inline]
 [<ffffffff825f9a5f>] fib6_run_gc+0xaf/0x230 net/ipv6/ip6_fib.c:1821
 [<ffffffff825f9bfd>] fib6_gc_timer_cb+0x1d/0x30 net/ipv6/ip6_fib.c:1836
 [<ffffffff812580cd>] call_timer_fn+0x18d/0x850 kernel/time/timer.c:1185
 [<ffffffff81258caf>] __run_timers kernel/time/timer.c:1261 [inline]
 [<ffffffff81258caf>] run_timer_softirq+0x51f/0xb70 kernel/time/timer.c:1444
 [<ffffffff8271b596>] __do_softirq+0x226/0xa3f kernel/softirq.c:273
 [<ffffffff810e187a>] invoke_softirq kernel/softirq.c:350 [inline]
 [<ffffffff810e187a>] irq_exit+0x10a/0x150 kernel/softirq.c:391
 [<ffffffff8271acce>] exiting_irq arch/x86/include/asm/apic.h:652 [inline]
 [<ffffffff8271acce>] smp_apic_timer_interrupt+0x7e/0xb0 arch/x86/kernel/apic/apic.c:926
 [<ffffffff8271a01d>] apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:768
 <EOI>  [<ffffffff81951e07>] ? avc_search_node security/selinux/avc.c:582 [inline]
 <EOI>  [<ffffffff81951e07>] ? avc_lookup+0xd7/0x1b0 security/selinux/avc.c:610
 [<ffffffff81951e07>] avc_search_node security/selinux/avc.c:582 [inline]
 [<ffffffff81951e07>] avc_lookup+0xd7/0x1b0 security/selinux/avc.c:610
 [<ffffffff819560d9>] avc_has_perm_noaudit security/selinux/avc.c:1110 [inline]
 [<ffffffff819560d9>] avc_has_perm+0x109/0x3a0 security/selinux/avc.c:1146
 [<ffffffff81962fe0>] task_has_perm+0x200/0x330 security/selinux/hooks.c:1525
 [<ffffffff81963134>] selinux_task_wait+0x24/0x30 security/selinux/hooks.c:3763
 [<ffffffff8194f903>] security_task_wait+0x73/0xb0 security/security.c:993
 [<ffffffff810daf5b>] wait_consider_task+0x28b/0x35b0 kernel/exit.c:1326
 [<ffffffff810de5d0>] do_wait_thread kernel/exit.c:1439 [inline]
 [<ffffffff810de5d0>] do_wait+0x350/0xa00 kernel/exit.c:1510
 [<ffffffff810df504>] SYSC_wait4 kernel/exit.c:1641 [inline]
 [<ffffffff810df504>] SyS_wait4+0x144/0x210 kernel/exit.c:1606
 [<ffffffff82718621>] entry_SYSCALL_64_fastpath+0x1e/0x9a
SELinux:  policydb string SE LVKux does not match my string SE Linux
SELinux:  policydb string SE LVKux does not match my string SE Linux