INFO: task kworker/u4:5:2830 blocked for more than 140 seconds. Not tainted 4.14.111 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:5 D26144 2830 2 0x80000000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 cleanup_net+0x11c/0x870 net/core/net_namespace.c:449 process_one_work+0x868/0x1610 kernel/workqueue.c:2114 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248 kthread+0x31c/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 INFO: task syz-executor.1:14797 blocked for more than 140 seconds. Not tainted 4.14.111 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28680 14797 7009 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 exp_funnel_lock kernel/rcu/tree_exp.h:295 [inline] _synchronize_rcu_expedited+0x6ca/0x8b0 kernel/rcu/tree_exp.h:596 synchronize_rcu_expedited kernel/rcu/tree_exp.h:724 [inline] synchronize_rcu_expedited+0x35/0xb0 kernel/rcu/tree_exp.h:713 synchronize_net+0x2f/0x50 net/core/dev.c:8217 nf_register_net_hook+0x651/0x940 net/netfilter/core.c:294 nf_register_net_hooks+0x4e/0xa0 net/netfilter/core.c:382 __ip_vs_init+0x272/0x420 net/netfilter/ipvs/ip_vs_core.c:2241 ops_init+0xac/0x3d0 net/core/net_namespace.c:118 setup_net+0x223/0x520 net/core/net_namespace.c:294 copy_net_ns+0x19f/0x440 net/core/net_namespace.c:418 create_new_namespaces+0x37b/0x720 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xab/0x1e0 kernel/nsproxy.c:206 SYSC_unshare kernel/fork.c:2379 [inline] SyS_unshare+0x2f3/0x7e0 kernel/fork.c:2329 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x458c29 RSP: 002b:00007f632f753c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000458c29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f632f7546d4 R13: 00000000004c7ccc R14: 00000000004ddf40 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1009: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4544 3 locks held by kworker/u4:5/2830: #0: ("%s""netns"){+.+.}, at: [] work_static include/linux/workqueue.h:199 [inline] #0: ("%s""netns"){+.+.}, at: [] set_work_data kernel/workqueue.c:619 [inline] #0: ("%s""netns"){+.+.}, at: [] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ("%s""netns"){+.+.}, at: [] process_one_work+0x76e/0x1610 kernel/workqueue.c:2085 #1: (net_cleanup_work){+.+.}, at: [] process_one_work+0x7ab/0x1610 kernel/workqueue.c:2089 #2: (net_mutex){+.+.}, at: [] cleanup_net+0x11c/0x870 net/core/net_namespace.c:449 2 locks held by getty/6965: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6966: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6967: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6968: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6969: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6970: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6971: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.1/14797: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:409 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1009 Comm: khungtaskd Not tainted 4.14.111 #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x138/0x19c lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x141/0x189 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:194 [inline] watchdog+0x5d8/0xb80 kernel/hung_task.c:250 kthread+0x31c/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5 Comm: kworker/u4:0 Not tainted 4.14.111 #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker task: ffff8880a9cc2140 task.stack: ffff8880a9cd0000 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:778 [inline] RIP: 0010:lock_acquire+0x1ea/0x430 kernel/locking/lockdep.c:3997 RSP: 0018:ffff8880a9cd7bf0 EFLAGS: 00000282 RAX: 1ffffffff0ee2965 RBX: ffff8880a9cc2140 RCX: 000000003b2aeda6 RDX: dffffc0000000000 RSI: ffff8880a9cc2a10 RDI: 0000000000000282 RBP: ffff8880a9cd7c38 R08: 00000000000075b3 R09: ffffffff88cb3158 R10: ffff8880a9cc2a10 R11: ffff8880a9cc2140 R12: ffff8880736ad428 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f840d38e140 CR3: 000000008c3d7000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x33/0x50 kernel/locking/spinlock.c:176 spin_lock_bh include/linux/spinlock.h:322 [inline] batadv_nc_purge_paths+0xcb/0x350 net/batman-adv/network-coding.c:450 batadv_nc_worker+0x23d/0x6d0 net/batman-adv/network-coding.c:727 process_one_work+0x868/0x1610 kernel/workqueue.c:2114 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248 kthread+0x31c/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 Code: 83 7c 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 f8 01 00 00 48 83 3d 6a 0f 29 06 00 0f 84 61 01 00 00 48 8b 7d c8 57 9d <0f> 1f 44 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 65