INFO: task kworker/0:1:12 blocked for more than 143 seconds. Not tainted 5.8.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:1 D22784 12 2 0x80004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:3453 [inline] __schedule+0x88a/0x1cb0 kernel/sched/core.c:4178 schedule+0xcd/0x2b0 kernel/sched/core.c:4253 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1873 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x168/0x270 kernel/sched/completion.c:138 kthread_stop+0x17d/0x770 kernel/kthread.c:595 hwrng_unregister+0x24f/0x330 drivers/char/hw_random/core.c:556 chaoskey_disconnect+0x216/0x290 drivers/usb/misc/chaoskey.c:232 usb_unbind_interface+0x1d8/0x8d0 drivers/usb/core/driver.c:436 __device_release_driver+0x3b7/0x6e0 drivers/base/dd.c:1113 device_release_driver_internal drivers/base/dd.c:1144 [inline] device_release_driver+0x26/0x40 drivers/base/dd.c:1167 bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:533 device_del+0x47c/0xd20 drivers/base/core.c:2857 usb_disable_device+0x387/0x930 drivers/usb/core/message.c:1245 usb_disconnect.cold+0x27d/0x780 drivers/usb/core/hub.c:2217 hub_port_connect drivers/usb/core/hub.c:5059 [inline] hub_port_connect_change drivers/usb/core/hub.c:5348 [inline] port_event drivers/usb/core/hub.c:5494 [inline] hub_event+0x1c93/0x4390 drivers/usb/core/hub.c:5576 process_one_work+0x94c/0x15f0 kernel/workqueue.c:2269 process_scheduled_works kernel/workqueue.c:2331 [inline] worker_thread+0x82b/0x1120 kernel/workqueue.c:2417 kthread+0x392/0x470 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Showing all locks held in the system: 5 locks held by kworker/0:1/12: #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x82b/0x15f0 kernel/workqueue.c:2240 #1: ffff8881da227da8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x85f/0x15f0 kernel/workqueue.c:2244 #2: ffff8881d4539218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:768 [inline] #2: ffff8881d4539218 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c5/0x4390 drivers/usb/core/hub.c:5522 #3: ffff8881cb5c4218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:768 [inline] #3: ffff8881cb5c4218 (&dev->mutex){....}-{3:3}, at: usb_disconnect.cold+0x43/0x780 drivers/usb/core/hub.c:2208 #4: ffff8881c61281a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:768 [inline] #4: ffff8881c61281a8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:936 [inline] #4: ffff8881c61281a8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal drivers/base/dd.c:1141 [inline] #4: ffff8881c61281a8 (&dev->mutex){....}-{3:3}, at: device_release_driver+0x1c/0x40 drivers/base/dd.c:1167 1 lock held by khungtaskd/23: #0: ffffffff873124a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x264 kernel/locking/lockdep.c:5779 1 lock held by in:imklog/253: 2 locks held by agetty/256: #0: ffff8881d2422098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000a0a2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156 2 locks held by agetty/257: #0: ffff8881cd8e7098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900009fe2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156 2 locks held by agetty/259: #0: ffff8881d5a3c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000a1e2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156 2 locks held by agetty/260: #0: ffff8881d3e41098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000a1a2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156 5 locks held by kworker/0:4/3084: 7 locks held by kworker/1:5/3109: #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x82b/0x15f0 kernel/workqueue.c:2240 #1: ffff8881ceb3fda8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x85f/0x15f0 kernel/workqueue.c:2244 #2: ffff8881d4511218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:768 [inline] #2: ffff8881d4511218 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c5/0x4390 drivers/usb/core/hub.c:5522 #3: ffff8881d8b26218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:768 [inline] #3: ffff8881d8b26218 (&dev->mutex){....}-{3:3}, at: usb_disconnect.cold+0x43/0x780 drivers/usb/core/hub.c:2208 #4: ffff8881adf7f1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:768 [inline] #4: ffff8881adf7f1a8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:936 [inline] #4: ffff8881adf7f1a8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal drivers/base/dd.c:1141 [inline] #4: ffff8881adf7f1a8 (&dev->mutex){....}-{3:3}, at: device_release_driver+0x1c/0x40 drivers/base/dd.c:1167 #5: ffffffff87e6c0a8 (rtnl_mutex){+.+.}-{3:3}, at: unregister_netdev+0xe/0x20 net/core/dev.c:10134 #6: ffffffff8731a1e0 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #6: ffffffff8731a1e0 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0xb7a/0xcf0 kernel/rcu/tree_exp.h:838 5 locks held by kworker/0:6/3136: 2 locks held by kworker/1:6/3276: #0: ffff8881da02a538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881da02a538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8881da02a538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8881da02a538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8881da02a538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8881da02a538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x82b/0x15f0 kernel/workqueue.c:2240 #1: ffff8881c8c6fda8 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x85f/0x15f0 kernel/workqueue.c:2244 5 locks held by kworker/0:8/3362: #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x82b/0x15f0 kernel/workqueue.c:2240 #1: ffff8881c562fda8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x85f/0x15f0 kernel/workqueue.c:2244 #2: ffff8881d4431218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:768 [inline] #2: ffff8881d4431218 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c5/0x4390 drivers/usb/core/hub.c:5522 #3: ffff8881c5f7c218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:768 [inline] #3: ffff8881c5f7c218 (&dev->mutex){....}-{3:3}, at: usb_disconnect.cold+0x43/0x780 drivers/usb/core/hub.c:2208 #4: ffff8881d8b041a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:768 [inline] #4: ffff8881d8b041a8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:936 [inline] #4: ffff8881d8b041a8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal drivers/base/dd.c:1141 [inline] #4: ffff8881d8b041a8 (&dev->mutex){....}-{3:3}, at: device_release_driver+0x1c/0x40 drivers/base/dd.c:1167 5 locks held by kworker/1:7/3428: 2 locks held by agetty/9964: #0: ffff8881c6970098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9001185d2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 5.8.0-rc3-syzkaller #0 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+0xf6/0x16e lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x74/0xb6 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1da/0x1f4 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd6a/0xfd0 kernel/hung_task.c:295 kthread+0x392/0x470 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 12975 Comm: systemd-udevd Not tainted 5.8.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:unwind_next_frame+0x54/0x1f60 arch/x86/kernel/unwind_orc.c:426 Code: 24 40 48 c7 44 24 48 f0 8b fb 86 48 c1 ed 03 48 c7 44 24 50 a0 74 10 81 48 8d 54 05 00 c7 02 f1 f1 f1 f1 c7 42 04 00 f3 f3 f3 <48> 89 fa 65 48 8b 34 25 28 00 00 00 48 89 b4 24 98 00 00 00 31 f6 RSP: 0018:ffff88819ff97968 EFLAGS: 00000a06 RAX: dffffc0000000000 RBX: ffff88819ff97a40 RCX: 1ffff11033ff2f01 RDX: ffffed1033ff2f35 RSI: ffffffff816d8019 RDI: ffff88819ff97a40 RBP: 1ffff11033ff2f35 R08: ffffffff885e2748 R09: 0000000000000001 R10: 0000000000027234 R11: ffff88819ff97e70 R12: ffff88819ff97af8 R13: 0000000000000000 R14: ffff8881c606b200 R15: ffff8881d1ca2000 FS: 00007fc81e56e8c0(0000) GS:ffff8881db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563582916188 CR3: 00000001d1c61000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0x116/0x160 mm/kasan/common.c:455 slab_free_hook mm/slub.c:1474 [inline] slab_free_freelist_hook+0x53/0x140 mm/slub.c:1507 slab_free mm/slub.c:3072 [inline] kmem_cache_free+0x84/0x2e0 mm/slub.c:3088 seq_release+0x5e/0x80 fs/seq_file.c:337 kernfs_fop_release+0xee/0x190 fs/kernfs/file.c:780 __fput+0x339/0x870 fs/file_table.c:281 task_work_run+0xdd/0x1a0 kernel/task_work.c:123 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:216 [inline] __prepare_exit_to_usermode+0x19e/0x1a0 arch/x86/entry/common.c:246 do_syscall_64+0x5c/0x90 arch/x86/entry/common.c:368 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fc81d377a4b Code: Bad RIP value. RSP: 002b:00007fff45f5ab98 EFLAGS: 00000206 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 000056358291dc60 RCX: 00007fc81d377a4b RDX: 00007fc81d69b900 RSI: 0000000000000001 RDI: 0000000000000007 RBP: 00007fc81d69c440 R08: 00007fc81e56e8c0 R09: 000056358291dc60 R10: 00007fc81e56e8c0 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000001000 R15: 00007fff45f5ad80