audit: type=1400 audit(1554658859.471:437): avc:  denied  { create } for  pid=20741 comm="syz-executor.4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0
===============================
[ INFO: suspicious RCU usage. ]
4.4.174+ #4 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
5 locks held by blkid/20766:
 #0:  (rcu_read_lock){......}, at: [<ffffffff819548bc>] INIT_LIST_HEAD include/linux/list.h:28 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff819548bc>] avc_compute_av+0xac/0x610 security/selinux/avc.c:973
 #1:  (((&net->ipv6.ip6_fib_timer))){+.-...}, at: [<ffffffff8125822e>] lockdep_copy_map include/linux/lockdep.h:165 [inline]
 #1:  (((&net->ipv6.ip6_fib_timer))){+.-...}, at: [<ffffffff8125822e>] call_timer_fn+0xde/0x850 kernel/time/timer.c:1175
 #2:  (fib6_gc_lock){+.-...}, at: [<ffffffff825fa33a>] spin_lock_bh include/linux/spinlock.h:307 [inline]
 #2:  (fib6_gc_lock){+.-...}, at: [<ffffffff825fa33a>] fib6_run_gc+0x3a/0x230 net/ipv6/ip6_fib.c:1811
 #3:  (rcu_read_lock){......}, at: [<ffffffff825f1ee0>] __fib6_clean_all+0x0/0x240 net/ipv6/ip6_fib.c:1698
 #4:  (&tb->tb6_lock){++--..}, at: [<ffffffff825f1fc8>] __fib6_clean_all+0xe8/0x240 net/ipv6/ip6_fib.c:1712

stack backtrace:
CPU: 1 PID: 20766 Comm: blkid Not tainted 4.4.174+ #4
 0000000000000000 f14876b66f4aa335 ffff8801db707940 ffffffff81aad1a1
 ffff8800b587c380 0000000000000000 0000000000000001 00000000000005b9
 ffff8801bcf2c740 ffff8801db707970 ffffffff813ab7d6 ffff8801db707b90
Call Trace:
 <IRQ>  [<ffffffff81aad1a1>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ>  [<ffffffff81aad1a1>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<ffffffff813ab7d6>] lockdep_rcu_suspicious.cold+0x10a/0x149 kernel/locking/lockdep.c:4305
 [<ffffffff825f9ada>] fib6_del+0x7ea/0xae0 net/ipv6/ip6_fib.c:1465
 [<ffffffff825fa06c>] fib6_clean_node+0x29c/0x500 net/ipv6/ip6_fib.c:1652
 [<ffffffff825f1830>] fib6_walk_continue+0x3e0/0x630 net/ipv6/ip6_fib.c:1578
 [<ffffffff825f1d71>] fib6_walk+0x91/0xe0 net/ipv6/ip6_fib.c:1623
 [<ffffffff825f1ea8>] fib6_clean_tree+0xe8/0x120 net/ipv6/ip6_fib.c:1697
 [<ffffffff825f1fe0>] __fib6_clean_all+0x100/0x240 net/ipv6/ip6_fib.c:1713
 [<ffffffff825fa3af>] fib6_clean_all net/ipv6/ip6_fib.c:1724 [inline]
 [<ffffffff825fa3af>] fib6_run_gc+0xaf/0x230 net/ipv6/ip6_fib.c:1821
 [<ffffffff825fa54d>] fib6_gc_timer_cb+0x1d/0x30 net/ipv6/ip6_fib.c:1836
 [<ffffffff812582dd>] call_timer_fn+0x18d/0x850 kernel/time/timer.c:1185
 [<ffffffff81258ebf>] __run_timers kernel/time/timer.c:1261 [inline]
 [<ffffffff81258ebf>] run_timer_softirq+0x51f/0xb70 kernel/time/timer.c:1444
 [<ffffffff8271bb16>] __do_softirq+0x226/0xa3f kernel/softirq.c:273
 [<ffffffff810e1a8a>] invoke_softirq kernel/softirq.c:350 [inline]
 [<ffffffff810e1a8a>] irq_exit+0x10a/0x150 kernel/softirq.c:391
 [<ffffffff8271b24e>] exiting_irq arch/x86/include/asm/apic.h:652 [inline]
 [<ffffffff8271b24e>] smp_apic_timer_interrupt+0x7e/0xb0 arch/x86/kernel/apic/apic.c:926
 [<ffffffff8271a59d>] apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:768
 <EOI>  [<ffffffff8271802f>] ? arch_local_irq_restore arch/x86/include/asm/paravirt.h:812 [inline]
 <EOI>  [<ffffffff8271802f>] ? __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:162 [inline]
 <EOI>  [<ffffffff8271802f>] ? _raw_spin_unlock_irqrestore+0x5f/0x70 kernel/locking/spinlock.c:191
 [<ffffffff8195365c>] spin_unlock_irqrestore include/linux/spinlock.h:362 [inline]
 [<ffffffff8195365c>] avc_reclaim_node security/selinux/avc.c:541 [inline]
 [<ffffffff8195365c>] avc_alloc_node security/selinux/avc.c:559 [inline]
 [<ffffffff8195365c>] avc_alloc_node+0x31c/0x3c0 security/selinux/avc.c:547
 [<ffffffff81954992>] avc_insert security/selinux/avc.c:670 [inline]
 [<ffffffff81954992>] avc_compute_av+0x182/0x610 security/selinux/avc.c:976
 [<ffffffff81956338>] avc_has_perm_noaudit+0x2a8/0x300 security/selinux/avc.c:1112
 [<ffffffff8196653f>] selinux_inode_permission+0x27f/0x4a0 security/selinux/hooks.c:2902
 [<ffffffff8194d569>] security_inode_permission+0xb9/0x100 security/security.c:600
 [<ffffffff814b6d86>] __inode_permission2+0x96/0x250 fs/namei.c:425
 [<ffffffff814b6fa2>] inode_permission2+0x32/0x110 fs/namei.c:475
 [<ffffffff814c4984>] may_open.isra.0+0x124/0x210 fs/namei.c:2781
 [<ffffffff814c5d80>] do_last fs/namei.c:3264 [inline]
 [<ffffffff814c5d80>] path_openat+0x1310/0x4470 fs/namei.c:3406
 [<ffffffff814ccab1>] do_filp_open+0x1a1/0x270 fs/namei.c:3440
 [<ffffffff81495668>] do_sys_open+0x2f8/0x600 fs/open.c:1038
 [<ffffffff8149599d>] SYSC_open fs/open.c:1056 [inline]
 [<ffffffff8149599d>] SyS_open+0x2d/0x40 fs/open.c:1051
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
audit: type=1400 audit(1554658860.551:438): avc:  denied  { create } for  pid=20787 comm="syz-executor.3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0
audit: type=1400 audit(1554658860.711:439): avc:  denied  { create } for  pid=20787 comm="syz-executor.3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0