bisecting fixing commit since 3dbdb38e286903ec220aaf1fb29a8d94297da246 building syzkaller on 55aa55c24fe77aae07d530662f91b4d50c4990f0 testing commit 3dbdb38e286903ec220aaf1fb29a8d94297da246 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1 kernel signature: be86f3f3b2899214e9271a92aa000cb0f01513f966a0a7a9a6242b89884a3943 run #0: crashed: INFO: task hung in hwrng_register run #1: crashed: INFO: task hung in drop_current_rng run #2: crashed: INFO: task hung in hwrng_register run #3: crashed: INFO: task hung in hwrng_register run #4: crashed: INFO: task hung in hwrng_register run #5: crashed: INFO: task hung in hwrng_register run #6: crashed: INFO: task hung in drop_current_rng run #7: crashed: INFO: task hung in hwrng_register run #8: crashed: INFO: task hung in hwrng_register run #9: crashed: INFO: task hung in hwrng_register run #10: crashed: INFO: task hung in hwrng_register run #11: crashed: INFO: task hung in hwrng_register run #12: crashed: INFO: task hung in hwrng_register run #13: crashed: INFO: task hung in hwrng_register run #14: crashed: INFO: task hung in hwrng_register run #15: crashed: INFO: task hung in hwrng_register run #16: crashed: INFO: task hung in hwrng_register run #17: crashed: INFO: task hung in hwrng_register run #18: crashed: INFO: task hung in hwrng_register run #19: crashed: INFO: task hung in hwrng_register testing current HEAD c500bee1c5b2f1d59b1081ac879d73268ab0ff17 testing commit c500bee1c5b2f1d59b1081ac879d73268ab0ff17 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1 kernel signature: 81de1cf4d4d11d61842002684788ea7f9483b15f0d0063e5640afd49f544328f run #0: crashed: INFO: task hung in hwrng_register run #1: crashed: INFO: task hung in drop_current_rng run #2: crashed: INFO: task hung in drop_current_rng run #3: crashed: INFO: task hung in hwrng_register run #4: crashed: INFO: task hung in hwrng_register run #5: crashed: INFO: task hung in hwrng_register run #6: crashed: INFO: task hung in hwrng_register run #7: crashed: INFO: task hung in hwrng_register run #8: crashed: INFO: task hung in hwrng_register run #9: crashed: INFO: task hung in hwrng_register revisions tested: 2, total time: 25m47.43858625s (build: 13m16.860002348s, test: 11m59.585657113s) the crash still happens on HEAD commit msg: Linux 5.14-rc4 crash: INFO: task hung in hwrng_register INFO: task kworker/0:1:7 blocked for more than 143 seconds. Not tainted 5.14.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:1 state:D stack:25008 pid: 7 ppid: 2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x907/0x26b0 kernel/sched/core.c:5940 schedule+0xd3/0x270 kernel/sched/core.c:6019 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6078 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7b6/0x10a0 kernel/locking/mutex.c:1104 hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:472 chaoskey_probe+0x7a6/0xb40 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x274/0x6a0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:517 [inline] really_probe+0x1b9/0xb70 drivers/base/dd.c:595 __driver_probe_device+0x2a6/0x460 drivers/base/dd.c:747 driver_probe_device+0x44/0x110 drivers/base/dd.c:777 __device_attach_driver+0x185/0x250 drivers/base/dd.c:894 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:427 __device_attach+0x1db/0x410 drivers/base/dd.c:965 bus_probe_device+0x19d/0x250 drivers/base/bus.c:487 device_add+0xa2f/0x1e00 drivers/base/core.c:3354 usb_set_configuration+0x9fc/0x1750 drivers/usb/core/message.c:2170 usb_generic_driver_probe+0x74/0xa0 drivers/usb/core/generic.c:238 usb_probe_device+0x95/0x240 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:517 [inline] really_probe+0x1b9/0xb70 drivers/base/dd.c:595 __driver_probe_device+0x2a6/0x460 drivers/base/dd.c:747 driver_probe_device+0x44/0x110 drivers/base/dd.c:777 __device_attach_driver+0x185/0x250 drivers/base/dd.c:894 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:427 __device_attach+0x1db/0x410 drivers/base/dd.c:965 bus_probe_device+0x19d/0x250 drivers/base/bus.c:487 device_add+0xa2f/0x1e00 drivers/base/core.c:3354 usb_new_device.cold+0x5cf/0xedf drivers/usb/core/hub.c:2563 hub_port_connect drivers/usb/core/hub.c:5348 [inline] hub_port_connect_change drivers/usb/core/hub.c:5488 [inline] port_event drivers/usb/core/hub.c:5634 [inline] hub_event+0x10a3/0x36c0 drivers/usb/core/hub.c:5716 process_one_work+0x84c/0x13d0 kernel/workqueue.c:2276 worker_thread+0x598/0x1040 kernel/workqueue.c:2422 kthread+0x38b/0x460 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task kworker/0:5:8693 blocked for more than 143 seconds. Not tainted 5.14.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:5 state:D stack:24664 pid: 8693 ppid: 2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x907/0x26b0 kernel/sched/core.c:5940 schedule+0xd3/0x270 kernel/sched/core.c:6019 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6078 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7b6/0x10a0 kernel/locking/mutex.c:1104 hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:472 chaoskey_probe+0x7a6/0xb40 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x274/0x6a0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:517 [inline] really_probe+0x1b9/0xb70 drivers/base/dd.c:595 __driver_probe_device+0x2a6/0x460 drivers/base/dd.c:747 driver_probe_device+0x44/0x110 drivers/base/dd.c:777 __device_attach_driver+0x185/0x250 drivers/base/dd.c:894 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:427 __device_attach+0x1db/0x410 drivers/base/dd.c:965 bus_probe_device+0x19d/0x250 drivers/base/bus.c:487 device_add+0xa2f/0x1e00 drivers/base/core.c:3354 usb_set_configuration+0x9fc/0x1750 drivers/usb/core/message.c:2170 usb_generic_driver_probe+0x74/0xa0 drivers/usb/core/generic.c:238 usb_probe_device+0x95/0x240 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:517 [inline] really_probe+0x1b9/0xb70 drivers/base/dd.c:595 __driver_probe_device+0x2a6/0x460 drivers/base/dd.c:747 driver_probe_device+0x44/0x110 drivers/base/dd.c:777 __device_attach_driver+0x185/0x250 drivers/base/dd.c:894 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:427 __device_attach+0x1db/0x410 drivers/base/dd.c:965 bus_probe_device+0x19d/0x250 drivers/base/bus.c:487 device_add+0xa2f/0x1e00 drivers/base/core.c:3354 usb_new_device.cold+0x5cf/0xedf drivers/usb/core/hub.c:2563 hub_port_connect drivers/usb/core/hub.c:5348 [inline] hub_port_connect_change drivers/usb/core/hub.c:5488 [inline] port_event drivers/usb/core/hub.c:5634 [inline] hub_event+0x10a3/0x36c0 drivers/usb/core/hub.c:5716 process_one_work+0x84c/0x13d0 kernel/workqueue.c:2276 worker_thread+0x598/0x1040 kernel/workqueue.c:2422 kthread+0x38b/0x460 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task kworker/1:5:10075 blocked for more than 144 seconds. Not tainted 5.14.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:5 state:D stack:24912 pid:10075 ppid: 2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x907/0x26b0 kernel/sched/core.c:5940 schedule+0xd3/0x270 kernel/sched/core.c:6019 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6078 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7b6/0x10a0 kernel/locking/mutex.c:1104 hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:472 chaoskey_probe+0x7a6/0xb40 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x274/0x6a0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:517 [inline] really_probe+0x1b9/0xb70 drivers/base/dd.c:595 __driver_probe_device+0x2a6/0x460 drivers/base/dd.c:747 driver_probe_device+0x44/0x110 drivers/base/dd.c:777 __device_attach_driver+0x185/0x250 drivers/base/dd.c:894 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:427 __device_attach+0x1db/0x410 drivers/base/dd.c:965 bus_probe_device+0x19d/0x250 drivers/base/bus.c:487 device_add+0xa2f/0x1e00 drivers/base/core.c:3354 usb_set_configuration+0x9fc/0x1750 drivers/usb/core/message.c:2170 usb_generic_driver_probe+0x74/0xa0 drivers/usb/core/generic.c:238 usb_probe_device+0x95/0x240 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:517 [inline] really_probe+0x1b9/0xb70 drivers/base/dd.c:595 __driver_probe_device+0x2a6/0x460 drivers/base/dd.c:747 driver_probe_device+0x44/0x110 drivers/base/dd.c:777 __device_attach_driver+0x185/0x250 drivers/base/dd.c:894 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:427 __device_attach+0x1db/0x410 drivers/base/dd.c:965 bus_probe_device+0x19d/0x250 drivers/base/bus.c:487 device_add+0xa2f/0x1e00 drivers/base/core.c:3354 usb_new_device.cold+0x5cf/0xedf drivers/usb/core/hub.c:2563 hub_port_connect drivers/usb/core/hub.c:5348 [inline] hub_port_connect_change drivers/usb/core/hub.c:5488 [inline] port_event drivers/usb/core/hub.c:5634 [inline] hub_event+0x10a3/0x36c0 drivers/usb/core/hub.c:5716 process_one_work+0x84c/0x13d0 kernel/workqueue.c:2276 worker_thread+0x598/0x1040 kernel/workqueue.c:2422 kthread+0x38b/0x460 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task kworker/1:7:10090 blocked for more than 145 seconds. Not tainted 5.14.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:7 state:D stack:24576 pid:10090 ppid: 2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x907/0x26b0 kernel/sched/core.c:5940 schedule+0xd3/0x270 kernel/sched/core.c:6019 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6078 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7b6/0x10a0 kernel/locking/mutex.c:1104 hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:472 chaoskey_probe+0x7a6/0xb40 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x274/0x6a0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:517 [inline] really_probe+0x1b9/0xb70 drivers/base/dd.c:595 __driver_probe_device+0x2a6/0x460 drivers/base/dd.c:747 driver_probe_device+0x44/0x110 drivers/base/dd.c:777 __device_attach_driver+0x185/0x250 drivers/base/dd.c:894 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:427 __device_attach+0x1db/0x410 drivers/base/dd.c:965 bus_probe_device+0x19d/0x250 drivers/base/bus.c:487 device_add+0xa2f/0x1e00 drivers/base/core.c:3354 usb_set_configuration+0x9fc/0x1750 drivers/usb/core/message.c:2170 usb_generic_driver_probe+0x74/0xa0 drivers/usb/core/generic.c:238 usb_probe_device+0x95/0x240 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:517 [inline] really_probe+0x1b9/0xb70 drivers/base/dd.c:595 __driver_probe_device+0x2a6/0x460 drivers/base/dd.c:747 driver_probe_device+0x44/0x110 drivers/base/dd.c:777 __device_attach_driver+0x185/0x250 drivers/base/dd.c:894 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:427 __device_attach+0x1db/0x410 drivers/base/dd.c:965 bus_probe_device+0x19d/0x250 drivers/base/bus.c:487 device_add+0xa2f/0x1e00 drivers/base/core.c:3354 usb_new_device.cold+0x5cf/0xedf drivers/usb/core/hub.c:2563 hub_port_connect drivers/usb/core/hub.c:5348 [inline] hub_port_connect_change drivers/usb/core/hub.c:5488 [inline] port_event drivers/usb/core/hub.c:5634 [inline] hub_event+0x10a3/0x36c0 drivers/usb/core/hub.c:5716 process_one_work+0x84c/0x13d0 kernel/workqueue.c:2276 worker_thread+0x598/0x1040 kernel/workqueue.c:2422 kthread+0x38b/0x460 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task kworker/1:8:10098 blocked for more than 145 seconds. Not tainted 5.14.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:8 state:D stack:25184 pid:10098 ppid: 2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x907/0x26b0 kernel/sched/core.c:5940 schedule+0xd3/0x270 kernel/sched/core.c:6019 schedule_timeout+0x19d/0x250 kernel/time/timer.c:1855 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+0x176/0x280 kernel/sched/completion.c:138 cleanup_rng drivers/char/hw_random/core.c:81 [inline] kref_put include/linux/kref.h:65 [inline] drop_current_rng+0x79/0xa0 drivers/char/hw_random/core.c:109 set_current_rng+0x1fb/0x310 drivers/char/hw_random/core.c:96 hwrng_register+0x328/0x500 drivers/char/hw_random/core.c:499 chaoskey_probe+0x7a6/0xb40 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x274/0x6a0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:517 [inline] really_probe+0x1b9/0xb70 drivers/base/dd.c:595 __driver_probe_device+0x2a6/0x460 drivers/base/dd.c:747 driver_probe_device+0x44/0x110 drivers/base/dd.c:777 __device_attach_driver+0x185/0x250 drivers/base/dd.c:894 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:427 __device_attach+0x1db/0x410 drivers/base/dd.c:965 bus_probe_device+0x19d/0x250 drivers/base/bus.c:487 device_add+0xa2f/0x1e00 drivers/base/core.c:3354 usb_set_configuration+0x9fc/0x1750 drivers/usb/core/message.c:2170 usb_generic_driver_probe+0x74/0xa0 drivers/usb/core/generic.c:238 usb_probe_device+0x95/0x240 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:517 [inline] really_probe+0x1b9/0xb70 drivers/base/dd.c:595 __driver_probe_device+0x2a6/0x460 drivers/base/dd.c:747 driver_probe_device+0x44/0x110 drivers/base/dd.c:777 __device_attach_driver+0x185/0x250 drivers/base/dd.c:894 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:427 __device_attach+0x1db/0x410 drivers/base/dd.c:965 bus_probe_device+0x19d/0x250 drivers/base/bus.c:487 device_add+0xa2f/0x1e00 drivers/base/core.c:3354 usb_new_device.cold+0x5cf/0xedf drivers/usb/core/hub.c:2563 hub_port_connect drivers/usb/core/hub.c:5348 [inline] hub_port_connect_change drivers/usb/core/hub.c:5488 [inline] port_event drivers/usb/core/hub.c:5634 [inline] hub_event+0x10a3/0x36c0 drivers/usb/core/hub.c:5716 process_one_work+0x84c/0x13d0 kernel/workqueue.c:2276 worker_thread+0x598/0x1040 kernel/workqueue.c:2422 kthread+0x38b/0x460 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task kworker/0:6:10140 blocked for more than 146 seconds. Not tainted 5.14.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:6 state:D stack:24944 pid:10140 ppid: 2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x907/0x26b0 kernel/sched/core.c:5940 schedule+0xd3/0x270 kernel/sched/core.c:6019 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6078 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7b6/0x10a0 kernel/locking/mutex.c:1104 hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:472 chaoskey_probe+0x7a6/0xb40 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x274/0x6a0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:517 [inline] really_probe+0x1b9/0xb70 drivers/base/dd.c:595 __driver_probe_device+0x2a6/0x460 drivers/base/dd.c:747 driver_probe_device+0x44/0x110 drivers/base/dd.c:777 __device_attach_driver+0x185/0x250 drivers/base/dd.c:894 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:427 __device_attach+0x1db/0x410 drivers/base/dd.c:965 bus_probe_device+0x19d/0x250 drivers/base/bus.c:487 device_add+0xa2f/0x1e00 drivers/base/core.c:3354 usb_set_configuration+0x9fc/0x1750 drivers/usb/core/message.c:2170 usb_generic_driver_probe+0x74/0xa0 drivers/usb/core/generic.c:238 usb_probe_device+0x95/0x240 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:517 [inline] really_probe+0x1b9/0xb70 drivers/base/dd.c:595 __driver_probe_device+0x2a6/0x460 drivers/base/dd.c:747 driver_probe_device+0x44/0x110 drivers/base/dd.c:777 __device_attach_driver+0x185/0x250 drivers/base/dd.c:894 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:427 __device_attach+0x1db/0x410 drivers/base/dd.c:965 bus_probe_device+0x19d/0x250 drivers/base/bus.c:487 device_add+0xa2f/0x1e00 drivers/base/core.c:3354 usb_new_device.cold+0x5cf/0xedf drivers/usb/core/hub.c:2563 hub_port_connect drivers/usb/core/hub.c:5348 [inline] hub_port_connect_change drivers/usb/core/hub.c:5488 [inline] port_event drivers/usb/core/hub.c:5634 [inline] hub_event+0x10a3/0x36c0 drivers/usb/core/hub.c:5716 process_one_work+0x84c/0x13d0 kernel/workqueue.c:2276 worker_thread+0x598/0x1040 kernel/workqueue.c:2422 kthread+0x38b/0x460 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Showing all locks held in the system: 6 locks held by kworker/0:1/7: #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:620 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13d0 kernel/workqueue.c:2247 #1: ffffc90000cc7db8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13d0 kernel/workqueue.c:2251 #2: ffff888020638220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #2: ffff888020638220 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36c0 drivers/usb/core/hub.c:5662 #3: ffff888042e16220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #3: ffff888042e16220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:940 #4: ffff88801f06c1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #4: ffff88801f06c1a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:940 #5: ffffffff8b361108 (rng_mutex){+.+.}-{3:3}, at: hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:472 1 lock held by khungtaskd/1645: #0: ffffffff8a9720c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 1 lock held by in:imklog/8133: #0: ffff888020b98ff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x9c/0xb0 fs/file.c:974 6 locks held by kworker/0:5/8693: #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:620 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13d0 kernel/workqueue.c:2247 #1: ffffc900020ffdb8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13d0 kernel/workqueue.c:2251 #2: ffff888020480220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #2: ffff888020480220 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36c0 drivers/usb/core/hub.c:5662 #3: ffff888042f14220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #3: ffff888042f14220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:940 #4: ffff888043b901a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #4: ffff888043b901a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:940 #5: ffffffff8b361108 (rng_mutex){+.+.}-{3:3}, at: hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:472 6 locks held by kworker/1:5/10075: #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:620 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13d0 kernel/workqueue.c:2247 #1: ffffc9000a517db8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13d0 kernel/workqueue.c:2251 #2: ffff888146b60220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #2: ffff888146b60220 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36c0 drivers/usb/core/hub.c:5662 #3: ffff888036de0220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #3: ffff888036de0220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:940 #4: ffff8880312461a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #4: ffff8880312461a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:940 #5: ffffffff8b361108 (rng_mutex){+.+.}-{3:3}, at: hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:472 6 locks held by kworker/1:7/10090: #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:620 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13d0 kernel/workqueue.c:2247 #1: ffffc9000a5b7db8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13d0 kernel/workqueue.c:2251 #2: ffff888020570220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #2: ffff888020570220 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36c0 drivers/usb/core/hub.c:5662 #3: ffff88802dda7220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #3: ffff88802dda7220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:940 #4: ffff88801802b1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #4: ffff88801802b1a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:940 #5: ffffffff8b361108 (rng_mutex){+.+.}-{3:3}, at: hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:472 6 locks held by kworker/1:8/10098: #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:620 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13d0 kernel/workqueue.c:2247 #1: ffffc9000a607db8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13d0 kernel/workqueue.c:2251 #2: ffff888146b48220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #2: ffff888146b48220 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36c0 drivers/usb/core/hub.c:5662 #3: ffff8880315d8220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #3: ffff8880315d8220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:940 #4: ffff88801b7d41a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #4: ffff88801b7d41a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:940 #5: ffffffff8b361108 (rng_mutex){+.+.}-{3:3}, at: hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:472 6 locks held by kworker/0:6/10140: #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:620 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff888017c65138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13d0 kernel/workqueue.c:2247 #1: ffffc9000a707db8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13d0 kernel/workqueue.c:2251 #2: ffff888020550220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #2: ffff888020550220 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36c0 drivers/usb/core/hub.c:5662 #3: ffff888042f26220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #3: ffff888042f26220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:940 #4: ffff888025fc01a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:754 [inline] #4: ffff888025fc01a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:940 #5: ffffffff8b361108 (rng_mutex){+.+.}-{3:3}, at: hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:472 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1645 Comm: khungtaskd Not tainted 5.14.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x57/0x7d lib/dump_stack.c:105 nmi_cpu_backtrace.cold+0x30/0x99 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x11f/0x170 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0x92e/0xc40 kernel/hung_task.c:295 kthread+0x38b/0x460 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: kworker/u4:2 Not tainted 5.14.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:rcu_preempt_read_enter kernel/rcu/tree_plugin.h:408 [inline] RIP: 0010:__rcu_read_lock+0x22/0xa0 kernel/rcu/tree_plugin.h:428 Code: 00 00 00 00 0f 1f 40 00 48 b8 00 00 00 00 00 fc ff df 53 65 48 8b 1c 25 00 f0 01 00 48 8d bb cc 03 00 00 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 4f 83 RSP: 0018:ffffc90000e2fc88 EFLAGS: 00000a07 RAX: dffffc0000000000 RBX: ffff888014585400 RCX: ffffc90000e2fc20 RDX: 1ffff110028b0af9 RSI: ffff8880266cb6c0 RDI: ffff8880145857cc RBP: ffff88800f869800 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: ffff8880b9f24288 R12: dffffc0000000000 R13: ffff88802acfcc00 R14: ffff88802acfd658 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0f8e876000 CR3: 000000001bc36000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock include/linux/rcupdate.h:685 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:404 [inline] batadv_nc_worker+0xe8/0xcc0 net/batman-adv/network-coding.c:715 process_one_work+0x84c/0x13d0 kernel/workqueue.c:2276 worker_thread+0x598/0x1040 kernel/workqueue.c:2422 kthread+0x38b/0x460 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295