=============================== [ 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 4 locks held by syz-executor.0/2346: #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70 #1: (fib6_gc_lock){+.-...}, at: [] spin_trylock_bh include/linux/spinlock.h:367 [inline] #1: (fib6_gc_lock){+.-...}, at: [] fib6_run_gc+0x18c/0x230 net/ipv6/ip6_fib.c:1812 #2: (rcu_read_lock){......}, at: [] __fib6_clean_all+0x0/0x240 net/ipv6/ip6_fib.c:1698 #3: (&tb->tb6_lock){++--..}, at: [] __fib6_clean_all+0xe8/0x240 net/ipv6/ip6_fib.c:1712 stack backtrace: CPU: 0 PID: 2346 Comm: syz-executor.0 Not tainted 4.4.174+ #4 0000000000000000 75d50b95ae185740 ffff8801bc38f650 ffffffff81aad1a1 ffff8801d0836e00 0000000000000000 0000000000000001 00000000000005b9 ffff8801d0e0af80 ffff8801bc38f680 ffffffff813ab7d6 ffff8801bc38f8a0 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 [] ndisc_netdev_event+0x2b0/0x360 net/ipv6/ndisc.c:1707 [] notifier_call_chain+0xb9/0x1e0 kernel/notifier.c:93 [] __raw_notifier_call_chain kernel/notifier.c:394 [inline] [] raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:401 [] call_netdevice_notifiers_info+0x56/0x70 net/core/dev.c:1643 [] call_netdevice_notifiers net/core/dev.c:1659 [inline] [] __dev_notify_flags+0x1a8/0x270 net/core/dev.c:6086 [] dev_change_flags+0xf7/0x140 net/core/dev.c:6117 [] devinet_ioctl+0xf30/0x15e0 net/ipv4/devinet.c:1052 [] inet_ioctl+0x10b/0x1a0 net/ipv4/af_inet.c:893 [] sock_do_ioctl+0x6a/0xb0 net/socket.c:896 [] sock_ioctl+0x24c/0x3d0 net/socket.c:982 [] vfs_ioctl fs/ioctl.c:43 [inline] [] file_ioctl fs/ioctl.c:470 [inline] [] do_vfs_ioctl+0x6e7/0xfa0 fs/ioctl.c:605 [] SYSC_ioctl fs/ioctl.c:622 [inline] [] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:613 [] entry_SYSCALL_64_fastpath+0x1e/0x9a audit_printk_skb: 192 callbacks suppressed audit: type=1400 audit(1552382635.674:37269): avc: denied { create } for pid=2398 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=0 audit: type=1400 audit(1552382635.674:37270): avc: denied { create } for pid=2401 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(1552382635.654:37268): avc: denied { create } for pid=2399 comm="syz-executor.1" 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(1552382635.794:37271): avc: denied { search } for pid=469 comm="udevd" name="/" dev="sysfs" ino=1 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:null_device_t:s0 tclass=dir permissive=0 audit: type=1400 audit(1552382635.794:37272): avc: denied { create } for pid=2399 comm="syz-executor.1" 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(1552382635.874:37273): avc: denied { create } for pid=2398 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=0 audit: type=1400 audit(1552382636.164:37274): avc: denied { search } for pid=469 comm="udevd" name="/" dev="sysfs" ino=1 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:null_device_t:s0 tclass=dir permissive=0 audit: type=1400 audit(1552382636.254:37275): avc: denied { search } for pid=469 comm="udevd" name="/" dev="sysfs" ino=1 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:null_device_t:s0 tclass=dir permissive=0 audit: type=1400 audit(1552382636.304:37276): avc: denied { search } for pid=469 comm="udevd" name="/" dev="sysfs" ino=1 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:null_device_t:s0 tclass=dir permissive=0 audit: type=1400 audit(1552382636.374:37277): avc: denied { search } for pid=469 comm="udevd" name="/" dev="sysfs" ino=1 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:null_device_t:s0 tclass=dir permissive=0 audit_printk_skb: 135 callbacks suppressed audit: type=1400 audit(1552382640.964:37324): avc: denied { search } for pid=469 comm="udevd" name="/" dev="sysfs" ino=1 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:null_device_t:s0 tclass=dir permissive=0 audit: type=1400 audit(1552382641.004:37325): avc: denied { create } for pid=2491 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=0 audit: type=1400 audit(1552382640.944:37323): avc: denied { create } for pid=2491 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=0 audit: type=1400 audit(1552382641.044:37326): avc: denied { search } for pid=469 comm="udevd" name="/" dev="sysfs" ino=1 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:null_device_t:s0 tclass=dir permissive=0 audit: type=1400 audit(1552382641.044:37327): avc: denied { search } for pid=469 comm="udevd" name="/" dev="sysfs" ino=1 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:null_device_t:s0 tclass=dir permissive=0 audit: type=1400 audit(1552382641.044:37328): avc: denied { search } for pid=469 comm="udevd" name="/" dev="sysfs" ino=1 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:null_device_t:s0 tclass=dir permissive=0 audit: type=1400 audit(1552382641.234:37329): avc: denied { search } for pid=469 comm="udevd" name="/" dev="sysfs" ino=1 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:null_device_t:s0 tclass=dir permissive=0 audit: type=1400 audit(1552382641.364:37330): avc: denied { search } for pid=469 comm="udevd" name="/" dev="sysfs" ino=1 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:null_device_t:s0 tclass=dir permissive=0 audit: type=1400 audit(1552382641.444:37331): avc: denied { search } for pid=469 comm="udevd" name="/" dev="sysfs" ino=1 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:null_device_t:s0 tclass=dir permissive=0 audit: type=1400 audit(1552382641.494:37332): avc: denied { search } for pid=469 comm="udevd" name="/" dev="sysfs" ino=1 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:null_device_t:s0 tclass=dir permissive=0