=============================== [ 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 udevd/2278: #0: (rcu_read_lock){......}, at: [] path_init+0x9a8/0x1820 fs/namei.c:2095 #1: (rcu_read_lock){......}, at: [] INIT_LIST_HEAD include/linux/list.h:28 [inline] #1: (rcu_read_lock){......}, at: [] avc_compute_av+0xac/0x610 security/selinux/avc.c:973 #2: (((&net->ipv6.ip6_fib_timer))){+.-...}, at: [] lockdep_copy_map include/linux/lockdep.h:165 [inline] #2: (((&net->ipv6.ip6_fib_timer))){+.-...}, at: [] call_timer_fn+0xde/0x850 kernel/time/timer.c:1175 #3: (fib6_gc_lock){+.-...}, at: [] spin_lock_bh include/linux/spinlock.h:307 [inline] #3: (fib6_gc_lock){+.-...}, at: [] fib6_run_gc+0x3a/0x230 net/ipv6/ip6_fib.c:1811 #4: (rcu_read_lock){......}, at: [] __fib6_clean_all+0x0/0x240 net/ipv6/ip6_fib.c:1698 #5: (&tb->tb6_lock){++--..}, at: [] __fib6_clean_all+0xe8/0x240 net/ipv6/ip6_fib.c:1712 stack backtrace: CPU: 0 PID: 2278 Comm: udevd Not tainted 4.4.174+ #4 0000000000000000 b3069af0809f4f5d ffff8801db607940 ffffffff81aad1a1 ffff8801d5e00380 0000000000000000 0000000000000001 00000000000005b9 ffff8801d40617c0 ffff8801db607970 ffffffff813ab7d6 ffff8801db607b90 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [] lockdep_rcu_suspicious.cold+0x10a/0x149 kernel/locking/lockdep.c:4305 [] fib6_del+0x7ea/0xae0 net/ipv6/ip6_fib.c:1465 [] fib6_clean_node+0x29c/0x500 net/ipv6/ip6_fib.c:1652 [] fib6_walk_continue+0x3e0/0x630 net/ipv6/ip6_fib.c:1578 [] fib6_walk+0x91/0xe0 net/ipv6/ip6_fib.c:1623 [] fib6_clean_tree+0xe8/0x120 net/ipv6/ip6_fib.c:1697 [] __fib6_clean_all+0x100/0x240 net/ipv6/ip6_fib.c:1713 [] fib6_clean_all net/ipv6/ip6_fib.c:1724 [inline] [] fib6_run_gc+0xaf/0x230 net/ipv6/ip6_fib.c:1821 [] fib6_gc_timer_cb+0x1d/0x30 net/ipv6/ip6_fib.c:1836 [] call_timer_fn+0x18d/0x850 kernel/time/timer.c:1185 [] __run_timers kernel/time/timer.c:1261 [inline] [] run_timer_softirq+0x51f/0xb70 kernel/time/timer.c:1444 [] __do_softirq+0x226/0xa3f kernel/softirq.c:273 [] invoke_softirq kernel/softirq.c:350 [inline] [] irq_exit+0x10a/0x150 kernel/softirq.c:391 [] exiting_irq arch/x86/include/asm/apic.h:652 [inline] [] smp_apic_timer_interrupt+0x7e/0xb0 arch/x86/kernel/apic/apic.c:926 [] apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:768 [] ? arch_local_irq_restore arch/x86/include/asm/paravirt.h:812 [inline] [] ? __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:162 [inline] [] ? _raw_spin_unlock_irqrestore+0x5f/0x70 kernel/locking/spinlock.c:191 [] spin_unlock_irqrestore include/linux/spinlock.h:362 [inline] [] avc_reclaim_node security/selinux/avc.c:541 [inline] [] avc_alloc_node security/selinux/avc.c:559 [inline] [] avc_alloc_node+0x31c/0x3c0 security/selinux/avc.c:547 [] avc_insert security/selinux/avc.c:670 [inline] [] avc_compute_av+0x182/0x610 security/selinux/avc.c:976 [] avc_has_perm_noaudit+0x2a8/0x300 security/selinux/avc.c:1112 [] selinux_inode_permission+0x27f/0x4a0 security/selinux/hooks.c:2902 [] security_inode_permission+0xb9/0x100 security/security.c:600 [] __inode_permission2+0x96/0x250 fs/namei.c:425 [] inode_permission2+0x32/0x110 fs/namei.c:475 [] may_lookup fs/namei.c:1706 [inline] [] link_path_walk+0x198/0x15e0 fs/namei.c:1970 [] path_parentat.isra.0+0x41/0x150 fs/namei.c:2250 [] filename_parentat.isra.0+0x18d/0x3e0 fs/namei.c:2272 [] filename_create+0xb3/0x460 fs/namei.c:3494 [] user_path_create fs/namei.c:3569 [inline] [] SYSC_symlinkat fs/namei.c:4066 [inline] [] SyS_symlinkat+0xee/0x240 fs/namei.c:4053 [] SYSC_symlink fs/namei.c:4086 [inline] [] SyS_symlink+0x23/0x30 fs/namei.c:4084 [] entry_SYSCALL_64_fastpath+0x1e/0x9a audit: type=1400 audit(1551964074.249:1539): avc: denied { create } for pid=22403 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(1551964074.289:1540): avc: denied { create } for pid=22409 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 audit: type=1400 audit(1551964074.329:1541): avc: denied { create } for pid=22403 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(1551964074.359:1542): avc: denied { create } for pid=22409 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 audit: type=1400 audit(1551964074.409:1543): avc: denied { create } for pid=22409 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 audit: type=1400 audit(1551964074.489:1544): avc: denied { create } for pid=22409 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 audit: type=1400 audit(1551964074.539:1545): avc: denied { create } for pid=22409 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 audit_printk_skb: 45 callbacks suppressed audit: type=1400 audit(1551964076.249:1562): avc: denied { create } for pid=22493 comm="syz-executor.2" 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(1551964076.329:1563): avc: denied { create } for pid=22493 comm="syz-executor.2" 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(1551964076.229:1561): avc: denied { create } for pid=22494 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(1551964076.409:1564): avc: denied { create } for pid=22493 comm="syz-executor.2" 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(1551964076.709:1565): avc: denied { create } for pid=22512 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(1551964076.979:1566): avc: denied { create } for pid=22518 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=0 audit: type=1400 audit(1551964077.179:1567): avc: denied { create } for pid=22518 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=0 audit: type=1400 audit(1551964077.179:1568): avc: denied { create } for pid=22529 comm="syz-executor.2" 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(1551964077.189:1569): avc: denied { create } for pid=22529 comm="syz-executor.2" 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(1551964077.199:1570): avc: denied { create } for pid=22529 comm="syz-executor.2" 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_printk_skb: 84 callbacks suppressed audit: type=1400 audit(1551964081.509:1599): avc: denied { create } for pid=22699 comm="syz-executor.2" 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(1551964082.069:1600): avc: denied { create } for pid=22722 comm="syz-executor.2" 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