INFO: task kworker/u4:0:7 blocked for more than 143 seconds. Not tainted 5.2.0-rc6+ #7 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:0 D21696 7 2 0x80004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:2818 [inline] __schedule+0x658/0x9e0 kernel/sched/core.c:3445 schedule+0x131/0x1d0 kernel/sched/core.c:3509 exp_funnel_lock kernel/rcu/tree_exp.h:309 [inline] synchronize_rcu_expedited+0x5a5/0x670 kernel/rcu/tree_exp.h:790 synchronize_net+0x3b/0x50 net/core/dev.c:9269 dev_deactivate_many+0x5fc/0x1310 net/sched/sch_generic.c:1201 __dev_close_many+0x1f7/0x360 net/core/dev.c:1476 dev_close_many+0x256/0x540 net/core/dev.c:1514 rollback_registered_many+0x49e/0x13a0 net/core/dev.c:8183 unregister_netdevice_many+0x4e/0x290 net/core/dev.c:9314 vti6_exit_batch_net+0x5ce/0x610 net/ipv6/ip6_vti.c:1148 ops_exit_list net/core/net_namespace.c:157 [inline] cleanup_net+0x64f/0x9f0 net/core/net_namespace.c:553 process_one_work+0x814/0x1130 kernel/workqueue.c:2269 worker_thread+0xc01/0x1640 kernel/workqueue.c:2415 kthread+0x325/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task syz-executor.0:2416 blocked for more than 143 seconds. Not tainted 5.2.0-rc6+ #7 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D25920 2416 19062 0x00004004 Call Trace: context_switch kernel/sched/core.c:2818 [inline] __schedule+0x658/0x9e0 kernel/sched/core.c:3445 schedule+0x131/0x1d0 kernel/sched/core.c:3509 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3568 __mutex_lock_common+0x14bf/0x2fc0 kernel/locking/mutex.c:1003 __mutex_lock kernel/locking/mutex.c:1073 [inline] mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1088 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 sock_do_ioctl+0x1d6/0x300 net/socket.c:1056 sock_ioctl+0x4f8/0x730 net/socket.c:1194 do_vfs_ioctl+0x7d4/0x1890 fs/ioctl.c:46 ksys_ioctl fs/ioctl.c:713 [inline] __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0xe3/0x120 fs/ioctl.c:718 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459519 Code: 48 89 98 e0 00 00 00 c7 04 24 00 00 00 00 48 8d 05 f4 2a 53 00 48 89 44 24 08 e8 72 0c fd ff 85 c0 0f 85 1c 02 00 00 48 8b 05 70 76 00 48 89 44 24 28 31 c0 eb 03 48 ff c0 48 83 f8 41 7d 5a RSP: 002b:00007f9bb0b52c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459519 RDX: 00000000200004c0 RSI: 0000001000008912 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9bb0b536d4 R13: 00000000004c08c0 R14: 00000000004d3620 R15: 00000000ffffffff INFO: task syz-executor.0:2423 blocked for more than 143 seconds. Not tainted 5.2.0-rc6+ #7 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D24064 2423 19062 0x00004004 Call Trace: context_switch kernel/sched/core.c:2818 [inline] __schedule+0x658/0x9e0 kernel/sched/core.c:3445 schedule+0x131/0x1d0 kernel/sched/core.c:3509 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3568 __mutex_lock_common+0x14bf/0x2fc0 kernel/locking/mutex.c:1003 __mutex_lock kernel/locking/mutex.c:1073 [inline] mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1088 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 sock_do_ioctl+0x1d6/0x300 net/socket.c:1056 sock_ioctl+0x4f8/0x730 net/socket.c:1194 do_vfs_ioctl+0x7d4/0x1890 fs/ioctl.c:46 ksys_ioctl fs/ioctl.c:713 [inline] __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0xe3/0x120 fs/ioctl.c:718 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459519 Code: 48 89 98 e0 00 00 00 c7 04 24 00 00 00 00 48 8d 05 f4 2a 53 00 48 89 44 24 08 e8 72 0c fd ff 85 c0 0f 85 1c 02 00 00 48 8b 05 70 76 00 48 89 44 24 28 31 c0 eb 03 48 ff c0 48 83 f8 41 7d 5a RSP: 002b:00007f9bb0b31c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459519 RDX: 00000000200004c0 RSI: 0000001000008912 RDI: 0000000000000005 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9bb0b326d4 R13: 00000000004c08c0 R14: 00000000004d3620 R15: 00000000ffffffff Showing all locks held in the system: 4 locks held by kworker/u4:0/7: #0: 00000000ed457446 ((wq_completion)netns){+.+.}, at: spin_unlock_irq include/linux/spinlock.h:388 [inline] #0: 00000000ed457446 ((wq_completion)netns){+.+.}, at: process_one_work+0x78a/0x1130 kernel/workqueue.c:2242 #1: 0000000004fccd0b (net_cleanup_work){+.+.}, at: process_one_work+0x7c9/0x1130 kernel/workqueue.c:2244 #2: 000000008101afb7 (pernet_ops_rwsem){++++}, at: cleanup_net+0xe6/0x9f0 net/core/net_namespace.c:520 #3: 00000000bc74cb4f (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 1 lock held by khungtaskd/1044: #0: 0000000012e0c81d (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 include/linux/rcupdate.h:207 2 locks held by rsyslogd/7929: #0: 0000000072a391fc (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x243/0x2e0 fs/file.c:801 #1: 0000000012e0c81d (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 include/linux/rcupdate.h:207 2 locks held by getty/8018: #0: 00000000acc6b178 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 000000007919839c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/8019: #0: 0000000060b7e00c (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 000000008bb32209 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/8020: #0: 00000000cd1fe7de (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 00000000f66cee0a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/8021: #0: 000000007c07bce8 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 00000000e6cb0f27 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/8022: #0: 000000009c687d28 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 00000000a4c4ce3b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/8023: #0: 000000001b2da498 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 00000000a0905f4f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/8024: #0: 000000007e8355ab (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 00000000a21960e2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 3 locks held by kworker/1:4/8096: #0: 000000003e9e9a86 ((wq_completion)ipv6_addrconf){+.+.}, at: spin_unlock_irq include/linux/spinlock.h:388 [inline] #0: 000000003e9e9a86 ((wq_completion)ipv6_addrconf){+.+.}, at: process_one_work+0x78a/0x1130 kernel/workqueue.c:2242 #1: 00000000783ec24c ((addr_chk_work).work){+.+.}, at: process_one_work+0x7c9/0x1130 kernel/workqueue.c:2244 #2: 00000000bc74cb4f (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 1 lock held by syz-executor.0/2416: #0: 00000000bc74cb4f (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 1 lock held by syz-executor.0/2423: #0: 00000000bc74cb4f (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1044 Comm: khungtaskd Not tainted 5.2.0-rc6+ #7 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d8/0x2f8 lib/dump_stack.c:113 nmi_cpu_backtrace+0x89/0x160 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x125/0x230 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace+0x17/0x20 include/linux/nmi.h:146 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xbb9/0xbd0 kernel/hung_task.c:289 kthread+0x325/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60