=============================== [ 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/15491: #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: 1 PID: 15491 Comm: udevd Not tainted 4.4.174+ #4 0000000000000000 31932af4227a5704 ffff8801db707940 ffffffff81aad1a1 ffff8800ba84b340 0000000000000000 0000000000000001 00000000000005b9 ffff8801cf10c740 ffff8801db707970 ffffffff813ab7d6 ffff8801db707b90 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_lookupat.isra.0+0x6a/0x3f0 fs/namei.c:2194 [] filename_lookup+0x1a4/0x3b0 fs/namei.c:2229 [] user_path_at_empty+0x43/0x50 fs/namei.c:2403 [] user_path_at include/linux/namei.h:52 [inline] [] vfs_fstatat+0xc6/0x170 fs/stat.c:106 [] vfs_lstat fs/stat.c:129 [inline] [] SYSC_newlstat fs/stat.c:283 [inline] [] SyS_newlstat+0x97/0x110 fs/stat.c:277 [] entry_SYSCALL_64_fastpath+0x1e/0x9a audit_printk_skb: 63 callbacks suppressed audit: type=1400 audit(1550002923.228:2052): avc: denied { create } for pid=21704 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=1 audit: type=1400 audit(1550002923.448:2053): avc: denied { write } for pid=21704 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=1 audit: type=1400 audit(1550002923.788:2054): avc: denied { create } for pid=21733 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 audit: type=1400 audit(1550002923.848:2055): avc: denied { read } for pid=21704 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=1 audit: type=1400 audit(1550002923.878:2056): avc: denied { create } for pid=21733 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 audit: type=1400 audit(1550002924.028:2057): avc: denied { create } for pid=21704 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=1 audit: type=1400 audit(1550002924.028:2058): avc: denied { write } for pid=21733 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 audit: type=1400 audit(1550002924.078:2059): avc: denied { write } for pid=21733 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 audit: type=1400 audit(1550002924.148:2060): avc: denied { read } for pid=21733 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 audit: type=1400 audit(1550002924.468:2061): avc: denied { create } for pid=21752 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=1 audit_printk_skb: 99 callbacks suppressed audit: type=1400 audit(1550002928.598:2095): avc: denied { create } for pid=21893 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=1 audit: type=1400 audit(1550002928.758:2096): avc: denied { write } for pid=21893 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=1 audit: type=1400 audit(1550002929.038:2097): avc: denied { read } for pid=21893 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=1 audit: type=1400 audit(1550002929.198:2098): avc: denied { create } for pid=21893 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=1 audit: type=1400 audit(1550002929.668:2099): avc: denied { create } for pid=21935 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=1 audit: type=1400 audit(1550002929.848:2100): avc: denied { write } for pid=21935 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=1 audit: type=1400 audit(1550002930.198:2101): avc: denied { read } for pid=21935 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=1 audit: type=1400 audit(1550002930.388:2102): avc: denied { create } for pid=21935 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=1 audit: type=1400 audit(1550002931.028:2103): avc: denied { create } for pid=21973 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=1 audit: type=1400 audit(1550002931.198:2104): avc: denied { write } for pid=21973 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=1