INFO: task syz-executor.5:13688 can't die for more than 143 seconds. syz-executor.5 D28072 13688 8692 0x00004004 Call Trace: context_switch kernel/sched/core.c:3265 [inline] __schedule+0x76e/0x17a0 kernel/sched/core.c:3937 schedule+0xd9/0x260 kernel/sched/core.c:4004 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1869 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 flush_workqueue+0x40f/0x14c0 kernel/workqueue.c:2826 nbd_start_device_ioctl drivers/block/nbd.c:1254 [inline] __nbd_ioctl drivers/block/nbd.c:1329 [inline] nbd_ioctl+0xb32/0xc50 drivers/block/nbd.c:1369 __blkdev_driver_ioctl block/ioctl.c:304 [inline] blkdev_ioctl+0xedb/0x1c20 block/ioctl.c:606 block_ioctl+0xee/0x130 fs/block_dev.c:1954 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4598e9 Code: 24 18 0f b6 05 2f d1 3b 01 3c 01 76 0a 48 8b 6c 24 18 48 83 c4 20 c3 75 07 e8 63 08 fd ff 0f 0b c6 05 11 d1 3b 01 01 48 b8 00 <00> 00 00 00 00 f0 7f 48 89 04 24 e8 a7 dd fa ff f2 0f 10 44 24 08 RSP: 002b:00007f6800465c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00000000004598e9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f68004666d4 R13: 00000000004c319f R14: 00000000004d6948 R15: 00000000ffffffff INFO: task syz-executor.5:13688 blocked for more than 143 seconds. Not tainted 5.3.0-rc6-next-20190830 #75 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28072 13688 8692 0x00004004 Call Trace: context_switch kernel/sched/core.c:3265 [inline] __schedule+0x76e/0x17a0 kernel/sched/core.c:3937 schedule+0xd9/0x260 kernel/sched/core.c:4004 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1869 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 flush_workqueue+0x40f/0x14c0 kernel/workqueue.c:2826 nbd_start_device_ioctl drivers/block/nbd.c:1254 [inline] __nbd_ioctl drivers/block/nbd.c:1329 [inline] nbd_ioctl+0xb32/0xc50 drivers/block/nbd.c:1369 __blkdev_driver_ioctl block/ioctl.c:304 [inline] blkdev_ioctl+0xedb/0x1c20 block/ioctl.c:606 block_ioctl+0xee/0x130 fs/block_dev.c:1954 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4598e9 Code: 24 18 0f b6 05 2f d1 3b 01 3c 01 76 0a 48 8b 6c 24 18 48 83 c4 20 c3 75 07 e8 63 08 fd ff 0f 0b c6 05 11 d1 3b 01 01 48 b8 00 <00> 00 00 00 00 f0 7f 48 89 04 24 e8 a7 dd fa ff f2 0f 10 44 24 08 RSP: 002b:00007f6800465c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00000000004598e9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f68004666d4 R13: 00000000004c319f R14: 00000000004d6948 R15: 00000000ffffffff Showing all locks held in the system: 3 locks held by kworker/u4:3/343: #0: ffff8880ae8348d8 (&rq->lock){-.-.}, at: newidle_balance+0xa32/0xe90 kernel/sched/fair.c:9845 #1: ffffffff88fa7f00 (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:5843 #2: ffff8880ae824c18 (&base->lock){-.-.}, at: lock_timer_base+0x56/0x1b0 kernel/time/timer.c:936 1 lock held by khungtaskd/1065: #0: ffffffff88fa7f00 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5337 2 locks held by kworker/u5:0/1524: #0: ffff8880a547b128 ((wq_completion)knbd5-recv){+.+.}, at: __write_once_size include/linux/compiler.h:203 [inline] #0: ffff8880a547b128 ((wq_completion)knbd5-recv){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a547b128 ((wq_completion)knbd5-recv){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880a547b128 ((wq_completion)knbd5-recv){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880a547b128 ((wq_completion)knbd5-recv){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline] #0: ffff8880a547b128 ((wq_completion)knbd5-recv){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline] #0: ffff8880a547b128 ((wq_completion)knbd5-recv){+.+.}, at: process_one_work+0x88b/0x1740 kernel/workqueue.c:2240 #1: ffff8880a5c47dc0 ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2244 1 lock held by rsyslogd/8550: #0: ffff88808e062160 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8639: #0: ffff88809ed13090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f4f2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8640: #0: ffff88809389a090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f352e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8641: #0: ffff88809c25c090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f472e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8642: #0: ffff8880a44d4090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f4b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8643: #0: ffff8880a008c090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f3f2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8644: #0: ffff88809d32b090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f532e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8645: #0: ffff888095fa7090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f212e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1065 Comm: khungtaskd Not tainted 5.3.0-rc6-next-20190830 #75 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:269 [inline] watchdog+0xc99/0x1360 kernel/hung_task.c:353 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 343 Comm: kworker/u4:3 Not tainted 5.3.0-rc6-next-20190830 #75 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:756 [inline] RIP: 0010:lock_release+0x4b1/0x960 kernel/locking/lockdep.c:4509 Code: 00 00 00 00 00 fc ff df 41 c7 84 24 9c 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 8c 03 00 00 48 83 3d bf 66 9a 07 00 <0f> 84 7f 01 00 00 48 8b bd 48 ff ff ff 57 9d 0f 1f 44 00 00 48 b8 RSP: 0018:ffff8880a8c1fc00 EFLAGS: 00000086 RAX: 1ffffffff11e5db4 RBX: 1ffff11015183f85 RCX: 1ffff1101518195a RDX: dffffc0000000000 RSI: 1ffff11015181966 RDI: ffff8880a8c0cadc RBP: ffff8880a8c1fcd0 R08: 0000000000000003 R09: ffff8880a8c0cad8 R10: fffffbfff138aef8 R11: ffffffff89c577c7 R12: ffff8880a8c0c240 R13: ffffffff8727549a R14: ffff8880a8c1fca8 R15: ffff8880a8c0c240 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 000000009fc61000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_release include/linux/rcupdate.h:213 [inline] rcu_read_unlock include/linux/rcupdate.h:653 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:411 [inline] batadv_nc_worker+0x225/0x760 net/batman-adv/network-coding.c:718 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352