audit: type=1400 audit(1548607009.339:1086): avc:  denied  { create } for  pid=27795 comm="syz-executor2" 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. ]
4.4.171+ #12 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 udevd/3044:
 #0:  (rcu_read_lock){......}, at: [<ffffffff814b80b8>] path_init+0x9a8/0x1820 fs/namei.c:2095
 #1:  (rcu_read_lock){......}, at: [<ffffffff8195445c>] INIT_LIST_HEAD include/linux/list.h:28 [inline]
 #1:  (rcu_read_lock){......}, at: [<ffffffff8195445c>] avc_compute_av+0xac/0x610 security/selinux/avc.c:973
 #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: [<ffffffff825f95ea>] spin_lock_bh include/linux/spinlock.h:307 [inline]
 #3:  (fib6_gc_lock){+.-...}, at: [<ffffffff825f95ea>] fib6_run_gc+0x3a/0x230 net/ipv6/ip6_fib.c:1811
 #4:  (rcu_read_lock){......}, at: [<ffffffff825f1190>] __fib6_clean_all+0x0/0x240 net/ipv6/ip6_fib.c:1698
 #5:  (&tb->tb6_lock){++--..}, at: [<ffffffff825f1278>] __fib6_clean_all+0xe8/0x240 net/ipv6/ip6_fib.c:1712

stack backtrace:
CPU: 0 PID: 3044 Comm: udevd Not tainted 4.4.171+ #12
 0000000000000000 39d544707e642cbf ffff8801db607940 ffffffff81aacd31
 ffff8801d57a5180 0000000000000000 0000000000000001 00000000000005b9
 ffff8801d0724740 ffff8801db607970 ffffffff813ab5d0 ffff8801db607b90
Call Trace:
 <IRQ>  [<ffffffff81aacd31>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ>  [<ffffffff81aacd31>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<ffffffff813ab5d0>] lockdep_rcu_suspicious.cold+0x10a/0x149 kernel/locking/lockdep.c:4305
 [<ffffffff825f8d8a>] fib6_del+0x7ea/0xae0 net/ipv6/ip6_fib.c:1465
 [<ffffffff825f931c>] fib6_clean_node+0x29c/0x500 net/ipv6/ip6_fib.c:1652
 [<ffffffff825f0ae0>] fib6_walk_continue+0x3e0/0x630 net/ipv6/ip6_fib.c:1578
 [<ffffffff825f1021>] fib6_walk+0x91/0xe0 net/ipv6/ip6_fib.c:1623
 [<ffffffff825f1158>] fib6_clean_tree+0xe8/0x120 net/ipv6/ip6_fib.c:1697
 [<ffffffff825f1290>] __fib6_clean_all+0x100/0x240 net/ipv6/ip6_fib.c:1713
 [<ffffffff825f965f>] fib6_clean_all net/ipv6/ip6_fib.c:1724 [inline]
 [<ffffffff825f965f>] fib6_run_gc+0xaf/0x230 net/ipv6/ip6_fib.c:1821
 [<ffffffff825f97fd>] 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
 [<ffffffff8271af56>] __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
 [<ffffffff8271a68e>] exiting_irq arch/x86/include/asm/apic.h:652 [inline]
 [<ffffffff8271a68e>] smp_apic_timer_interrupt+0x7e/0xb0 arch/x86/kernel/apic/apic.c:926
 [<ffffffff827199dd>] apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:768
 <EOI>  [<ffffffff8271748f>] ? arch_local_irq_restore arch/x86/include/asm/paravirt.h:812 [inline]
 <EOI>  [<ffffffff8271748f>] ? __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:162 [inline]
 <EOI>  [<ffffffff8271748f>] ? _raw_spin_unlock_irqrestore+0x5f/0x70 kernel/locking/spinlock.c:191
 [<ffffffff819531fc>] spin_unlock_irqrestore include/linux/spinlock.h:362 [inline]
 [<ffffffff819531fc>] avc_reclaim_node security/selinux/avc.c:541 [inline]
 [<ffffffff819531fc>] avc_alloc_node security/selinux/avc.c:559 [inline]
 [<ffffffff819531fc>] avc_alloc_node+0x31c/0x3c0 security/selinux/avc.c:547
 [<ffffffff81954532>] avc_insert security/selinux/avc.c:670 [inline]
 [<ffffffff81954532>] avc_compute_av+0x182/0x610 security/selinux/avc.c:976
 [<ffffffff81955ed8>] avc_has_perm_noaudit+0x2a8/0x300 security/selinux/avc.c:1112
 [<ffffffff819660df>] selinux_inode_permission+0x27f/0x4a0 security/selinux/hooks.c:2902
 [<ffffffff8194d139>] security_inode_permission+0xb9/0x100 security/security.c:600
 [<ffffffff814b6966>] __inode_permission2+0x96/0x250 fs/namei.c:425
 [<ffffffff814b6b82>] inode_permission2+0x32/0x110 fs/namei.c:475
 [<ffffffff814c1778>] may_lookup fs/namei.c:1706 [inline]
 [<ffffffff814c1778>] link_path_walk+0x198/0x15e0 fs/namei.c:1970
 [<ffffffff814c3a1a>] path_lookupat.isra.0+0x6a/0x3f0 fs/namei.c:2194
 [<ffffffff814caa74>] filename_lookup+0x1a4/0x3b0 fs/namei.c:2229
 [<ffffffff814cadd3>] user_path_at_empty+0x43/0x50 fs/namei.c:2403
 [<ffffffff814a4ec6>] user_path_at include/linux/namei.h:52 [inline]
 [<ffffffff814a4ec6>] vfs_fstatat+0xc6/0x170 fs/stat.c:106
 [<ffffffff814a60d4>] vfs_stat fs/stat.c:123 [inline]
 [<ffffffff814a60d4>] SYSC_newstat fs/stat.c:270 [inline]
 [<ffffffff814a60d4>] SyS_newstat+0x94/0x100 fs/stat.c:266
 [<ffffffff82717fe1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
audit_printk_skb: 9 callbacks suppressed
audit: type=1400 audit(1548607011.579:1090): avc:  denied  { create } for  pid=27829 comm="syz-executor0" 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(1548607012.279:1091): avc:  denied  { create } for  pid=27829 comm="syz-executor0" 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(1548607014.929:1092): avc:  denied  { create } for  pid=27913 comm="syz-executor0" 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(1548607015.019:1093): avc:  denied  { create } for  pid=27915 comm="syz-executor2" 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(1548607017.159:1094): avc:  denied  { create } for  pid=27956 comm="syz-executor2" 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(1548607017.359:1095): avc:  denied  { create } for  pid=27967 comm="syz-executor0" 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(1548607019.119:1096): avc:  denied  { create } for  pid=28001 comm="syz-executor2" 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(1548607019.449:1097): avc:  denied  { create } for  pid=28014 comm="syz-executor0" 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