INFO: task kworker/0:3:9048 blocked for more than 140 seconds. Not tainted 4.14.261-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:3 D27216 9048 2 0x80000000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 hub_port_connect drivers/usb/core/hub.c:4921 [inline] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] port_event drivers/usb/core/hub.c:5250 [inline] hub_event+0x15ea/0x3f60 drivers/usb/core/hub.c:5330 process_one_work+0x793/0x14a0 kernel/workqueue.c:2117 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 INFO: task kworker/0:6:11985 blocked for more than 140 seconds. Not tainted 4.14.261-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:6 D28280 11985 2 0x80000000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 hub_port_connect drivers/usb/core/hub.c:4921 [inline] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] port_event drivers/usb/core/hub.c:5250 [inline] hub_event+0x15ea/0x3f60 drivers/usb/core/hub.c:5330 process_one_work+0x793/0x14a0 kernel/workqueue.c:2117 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Showing all locks held in the system: 5 locks held by kworker/1:0/18: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1082 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3f60 drivers/usb/core/hub.c:5276 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2936 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4920 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x15c0/0x3f60 drivers/usb/core/hub.c:5330 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4921 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_event+0x15ea/0x3f60 drivers/usb/core/hub.c:5330 1 lock held by khungtaskd/1532: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 5 locks held by kworker/0:3/9048: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1082 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3f60 drivers/usb/core/hub.c:5276 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2936 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4920 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x15c0/0x3f60 drivers/usb/core/hub.c:5330 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4921 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_event+0x15ea/0x3f60 drivers/usb/core/hub.c:5330 5 locks held by kworker/0:5/11307: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1082 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3f60 drivers/usb/core/hub.c:5276 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2936 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4920 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x15c0/0x3f60 drivers/usb/core/hub.c:5330 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4921 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_event+0x15ea/0x3f60 drivers/usb/core/hub.c:5330 5 locks held by kworker/0:6/11985: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1082 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3f60 drivers/usb/core/hub.c:5276 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2936 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4920 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x15c0/0x3f60 drivers/usb/core/hub.c:5330 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4921 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_event+0x15ea/0x3f60 drivers/usb/core/hub.c:5330 5 locks held by kworker/1:3/10574: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1082 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3f60 drivers/usb/core/hub.c:5276 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2936 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4920 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x15c0/0x3f60 drivers/usb/core/hub.c:5330 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4921 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_event+0x15ea/0x3f60 drivers/usb/core/hub.c:5330 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1532 Comm: khungtaskd Not tainted 4.14.261-syzkaller #0 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+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 2858 Comm: kworker/u4:4 Not tainted 4.14.261-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker task: ffff8880ac01a0c0 task.stack: ffff8880ac078000 RIP: 0010:debug_lockdep_rcu_enabled kernel/rcu/update.c:300 [inline] RIP: 0010:debug_lockdep_rcu_enabled+0x9f/0xe0 kernel/rcu/update.c:297 RSP: 0018:ffff8880ac07fc38 EFLAGS: 00000002 RAX: 0000000000000007 RBX: ffff8880ac01a0c0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff8880ac01a944 RBP: ffffffff88f77980 R08: 0000000000000000 R09: 0000000000020012 R10: 0000000000000000 R11: ffff8880ac01a0c0 R12: ffffffff86eb30d0 R13: ffff8880ac01a0c0 R14: ffff88813fe468c0 R15: ffff8880a4a43c00 FS: 0000000000000000(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2637830741 CR3: 0000000019fd4000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x5a6/0x870 kernel/locking/lockdep.c:4016 rcu_lock_release include/linux/rcupdate.h:247 [inline] rcu_read_unlock include/linux/rcupdate.h:685 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:422 [inline] batadv_nc_worker+0x5a7/0xc50 net/batman-adv/network-coding.c:728 process_one_work+0x793/0x14a0 kernel/workqueue.c:2117 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 02 00 48 8d bb 84 08 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 <84> d2 75 32 8b 93 84 08 00 00 31 c0 5b 85 d2 0f 94 c0 c3 31 c0 ---------------- Code disassembly (best guess): 0: 02 00 add (%rax),%al 2: 48 8d bb 84 08 00 00 lea 0x884(%rbx),%rdi 9: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 10: fc ff df 13: 48 89 fa mov %rdi,%rdx 16: 48 c1 ea 03 shr $0x3,%rdx 1a: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx 1e: 48 89 f8 mov %rdi,%rax 21: 83 e0 07 and $0x7,%eax 24: 83 c0 03 add $0x3,%eax 27: 38 d0 cmp %dl,%al 29: 7c 04 jl 0x2f * 2b: 84 d2 test %dl,%dl <-- trapping instruction 2d: 75 32 jne 0x61 2f: 8b 93 84 08 00 00 mov 0x884(%rbx),%edx 35: 31 c0 xor %eax,%eax 37: 5b pop %rbx 38: 85 d2 test %edx,%edx 3a: 0f 94 c0 sete %al 3d: c3 retq 3e: 31 c0 xor %eax,%eax