audit: type=1400 audit(1552936811.819:1216): avc:  denied  { create } for  pid=24092 comm="syz-executor.0" 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=1
===============================
[ 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
6 locks held by blkid/24144:
 #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff81409d77>] vm_mmap_pgoff+0x137/0x1c0 mm/util.c:295
 #1:  (policy_rwlock){.+.+..}, at: [<ffffffff8199f685>] security_compute_av+0x35/0x770 security/selinux/ss/services.c:1096
 #2:  (((&net->ipv6.ip6_fib_timer))){+.-...}, at: [<ffffffff8125822e>] lockdep_copy_map include/linux/lockdep.h:165 [inline]
 #2:  (((&net->ipv6.ip6_fib_timer))){+.-...}, at: [<ffffffff8125822e>] call_timer_fn+0xde/0x850 kernel/time/timer.c:1175
 #3:  (fib6_gc_lock){+.-...}, at: [<ffffffff825fa33a>] spin_lock_bh include/linux/spinlock.h:307 [inline]
 #3:  (fib6_gc_lock){+.-...}, at: [<ffffffff825fa33a>] fib6_run_gc+0x3a/0x230 net/ipv6/ip6_fib.c:1811
 #4:  (rcu_read_lock){......}, at: [<ffffffff825f1ee0>] __fib6_clean_all+0x0/0x240 net/ipv6/ip6_fib.c:1698
 #5:  (&tb->tb6_lock){++--..}, at: [<ffffffff825f1fc8>] __fib6_clean_all+0xe8/0x240 net/ipv6/ip6_fib.c:1712

stack backtrace:
CPU: 0 PID: 24144 Comm: blkid Not tainted 4.4.174+ #4
 0000000000000000 62b08608bfdf56ac ffff8801db607940 ffffffff81aad1a1
 ffff8801c671c700 0000000000000000 0000000000000001 00000000000005b9
 ffff8801ba2a8000 ffff8801db607970 ffffffff813ab7d6 ffff8801db607b90
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>  [<ffffffff81ae69ec>] ? flex_array_get_ptr+0x2c/0x70 lib/flex_array.c:353
 [<ffffffff81985511>] avtab_search_node+0x1d1/0x490 security/selinux/ss/avtab.c:229
 [<ffffffff819a8cf8>] cond_compute_av+0x58/0x300 security/selinux/ss/conditional.c:644
 [<ffffffff8199ca07>] context_struct_compute_av+0x757/0x1080 security/selinux/ss/services.c:707
 [<ffffffff8199f8e0>] security_compute_av+0x290/0x770 security/selinux/ss/services.c:1126
 [<ffffffff819548d9>] avc_compute_av+0xc9/0x610 security/selinux/avc.c:974
 [<ffffffff81956338>] avc_has_perm_noaudit+0x2a8/0x300 security/selinux/avc.c:1112
 [<ffffffff8196f916>] cred_has_capability.isra.0+0x106/0x250 security/selinux/hooks.c:1576
 [<ffffffff8196fac8>] selinux_vm_enough_memory+0x68/0x90 security/selinux/hooks.c:2146
 [<ffffffff8194bf17>] security_vm_enough_memory_mm+0x77/0xc0 security/security.c:230
 [<ffffffff81448668>] mmap_region+0x5a8/0x1090 mm/mmap.c:1646
 [<ffffffff81449634>] do_mmap+0x4e4/0xa20 mm/mmap.c:1473
 [<ffffffff81409daa>] do_mmap_pgoff include/linux/mm.h:1917 [inline]
 [<ffffffff81409daa>] vm_mmap_pgoff+0x16a/0x1c0 mm/util.c:296
 [<ffffffff81447b9d>] SYSC_mmap_pgoff mm/mmap.c:1523 [inline]
 [<ffffffff81447b9d>] SyS_mmap_pgoff+0x14d/0x1b0 mm/mmap.c:1481
 [<ffffffff81016bf6>] SYSC_mmap arch/x86/kernel/sys_x86_64.c:95 [inline]
 [<ffffffff81016bf6>] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:86
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
audit: type=1400 audit(1552936814.649:1217): avc:  denied  { create } for  pid=24201 comm="syz-executor.5" 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=1
audit: type=1400 audit(1552936814.809:1218): avc:  denied  { write } for  pid=24201 comm="syz-executor.5" 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=1
audit: type=1400 audit(1552936815.019:1219): avc:  denied  { read } for  pid=24201 comm="syz-executor.5" 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=1