=============================== [ INFO: suspicious RCU usage. ] 4.9.96-g71fce1e #13 Not tainted ------------------------------- kernel/rcu/tree_plugin.h:672 Illegal synchronize_rcu() in RCU read-side critical section! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 0 3 locks held by udevd/2040: #0: (rcu_read_lock){......}, at: [] path_init+0xf4d/0x1580 include/linux/compiler.h:243 #1: (rcu_read_lock){......}, at: [] INIT_LIST_HEAD include/linux/list.h:28 [inline] #1: (rcu_read_lock){......}, at: [] avc_compute_av+0xb0/0x610 security/selinux/avc.c:975 #2: (rcu_callback){......}, at: [] __rcu_reclaim kernel/rcu/rcu.h:108 [inline] #2: (rcu_callback){......}, at: [] rcu_do_batch kernel/rcu/tree.c:2789 [inline] #2: (rcu_callback){......}, at: [] invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline] #2: (rcu_callback){......}, at: [] __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline] #2: (rcu_callback){......}, at: [] rcu_process_callbacks+0x98e/0x12b0 kernel/rcu/tree.c:3037 stack backtrace: CPU: 1 PID: 2040 Comm: udevd Not tainted 4.9.96-g71fce1e #13 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801db307d60 ffffffff81eb0b69 ffff8801cc85e000 0000000000000000 0000000000000002 ffffffff83a6da00 ffff88019fbeab58 ffff8801db307d90 ffffffff81423fe9 ffff88019fbeaa00 ffff8801b5832a48 ffff8801b5832248 Call Trace: [ 1306.003971] [] __dump_stack lib/dump_stack.c:15 [inline] [ 1306.003971] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] lockdep_rcu_suspicious.cold.48+0x110/0x141 kernel/locking/lockdep.c:4455 [] synchronize_rcu+0x68/0x90 kernel/rcu/tree_plugin.h:669 [] __l2tp_session_unhash+0x38a/0x520 net/l2tp/l2tp_core.c:1796 [] l2tp_tunnel_closeall+0x1f7/0x350 net/l2tp/l2tp_core.c:1364 [] l2tp_tunnel_destruct+0x2f2/0x590 net/l2tp/l2tp_core.c:1324 [] __sk_destruct+0x55/0x590 net/core/sock.c:1428 [] __rcu_reclaim kernel/rcu/rcu.h:118 [inline] [] rcu_do_batch kernel/rcu/tree.c:2789 [inline] [] invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline] [] __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline] [] rcu_process_callbacks+0x8ae/0x12b0 kernel/rcu/tree.c:3037 [] __do_softirq+0x20b/0x937 kernel/softirq.c:284 [] invoke_softirq kernel/softirq.c:364 [inline] [] irq_exit+0x147/0x190 kernel/softirq.c:405 [] exiting_irq arch/x86/include/asm/apic.h:659 [inline] [] smp_apic_timer_interrupt+0x81/0xa0 arch/x86/kernel/apic/apic.c:960 [] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:648 [] spin_unlock_irqrestore include/linux/spinlock.h:362 [inline] [] avc_reclaim_node security/selinux/avc.c:543 [inline] [] avc_alloc_node+0x289/0x3d0 security/selinux/avc.c:561 [] avc_insert security/selinux/avc.c:672 [inline] [] avc_compute_av+0x178/0x610 security/selinux/avc.c:978 [] avc_has_perm_noaudit+0x319/0x450 security/selinux/avc.c:1114 [] selinux_inode_permission+0x32d/0x4b0 security/selinux/hooks.c:3038 [] security_inode_permission+0xb9/0x100 security/security.c:611 [] __inode_permission2+0x93/0x2d0 fs/namei.c:435 [] inode_permission2+0x2f/0x110 fs/namei.c:485 [] may_lookup fs/namei.c:1683 [inline] [] link_path_walk+0x195/0x1200 fs/namei.c:2064 [] path_lookupat.isra.41+0x1b4/0x410 fs/namei.c:2282 [] filename_lookup.part.55+0x177/0x370 fs/namei.c:2317 [] filename_lookup fs/namei.c:2310 [inline] [] user_path_at_empty+0x53/0x70 fs/namei.c:2578 [] SYSC_readlinkat fs/stat.c:327 [inline] [] SyS_readlinkat fs/stat.c:315 [inline] [] SYSC_readlink fs/stat.c:352 [inline] [] SyS_readlink+0xe6/0x320 fs/stat.c:349 [] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb ODEBUG: object ffff8801db307ce8 is NOT on stack ffff8801cc9c0000, but annotated ------------[ cut here ]------------ WARNING: CPU: 1 PID: 2040 at lib/debugobjects.c:303 debug_object_is_on_stack lib/debugobjects.c:303 [inline] WARNING: CPU: 1 PID: 2040 at lib/debugobjects.c:303 __debug_object_init.cold.10+0x6b/0x2b0 lib/debugobjects.c:329