bisecting fixing commit since f40ddce88593482919761f74910f42f4b84c004b building syzkaller on 98682e5e2aefc9aad61354f4f3ac93be96002a2a testing commit f40ddce88593482919761f74910f42f4b84c004b with gcc (GCC) 10.2.1 20210217 kernel signature: a20fdda6284e1de4805076b3f724e927513bee772a53c4f27dc22d1ef7831f86 run #0: crashed: INFO: task hung in drop_current_rng run #1: crashed: INFO: task hung in hwrng_register 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 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 drop_current_rng 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 f5b6eb1e018203913dfefcf6fa988649ad11ad6e testing commit f5b6eb1e018203913dfefcf6fa988649ad11ad6e with gcc (GCC) 10.2.1 20210217 kernel signature: 8aa03480380563fbe6a945b8aee5f4879e78fb561f3e8fa450cd659c28ae0f45 run #0: crashed: INFO: task hung in hwrng_register run #1: crashed: INFO: task hung in hwrng_register 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 drop_current_rng revisions tested: 2, total time: 27m38.409397305s (build: 14m43.343330414s, test: 11m55.836765063s) the crash still happens on HEAD commit msg: Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux crash: INFO: task hung in drop_current_rng INFO: task kworker/0:1:7 blocked for more than 143 seconds. Not tainted 5.13.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:1 state:D stack:25312 pid: 7 ppid: 2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x8de/0x2390 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_timeout+0x19d/0x210 kernel/time/timer.c:1868 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 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:505 chaoskey_probe+0x7a6/0xb50 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x274/0x6a0 drivers/usb/core/driver.c:396 really_probe+0x1fd/0xd10 drivers/base/dd.c:576 driver_probe_device+0x21a/0x3b0 drivers/base/dd.c:763 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:431 __device_attach+0x1db/0x410 drivers/base/dd.c:938 bus_probe_device+0x19d/0x250 drivers/base/bus.c:491 device_add+0x9f0/0x1d60 drivers/base/core.c:3324 usb_set_configuration+0x9fc/0x1750 drivers/usb/core/message.c:2164 usb_generic_driver_probe+0x74/0xa0 drivers/usb/core/generic.c:238 usb_probe_device+0x98/0x240 drivers/usb/core/driver.c:293 really_probe+0x1fd/0xd10 drivers/base/dd.c:576 driver_probe_device+0x21a/0x3b0 drivers/base/dd.c:763 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:431 __device_attach+0x1db/0x410 drivers/base/dd.c:938 bus_probe_device+0x19d/0x250 drivers/base/bus.c:491 device_add+0x9f0/0x1d60 drivers/base/core.c:3324 usb_new_device.cold+0x69a/0xee1 drivers/usb/core/hub.c:2556 hub_port_connect drivers/usb/core/hub.c:5276 [inline] hub_port_connect_change drivers/usb/core/hub.c:5416 [inline] port_event drivers/usb/core/hub.c:5562 [inline] hub_event+0x10a3/0x36d0 drivers/usb/core/hub.c:5644 process_one_work+0x84c/0x13b0 kernel/workqueue.c:2276 worker_thread+0x598/0xf80 kernel/workqueue.c:2422 kthread+0x36f/0x450 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 INFO: task kworker/1:0:19 blocked for more than 143 seconds. Not tainted 5.13.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:0 state:D stack:25440 pid: 19 ppid: 2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x8de/0x2390 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5285 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7d4/0x10c0 kernel/locking/mutex.c:1104 hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:478 chaoskey_probe+0x7a6/0xb50 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x274/0x6a0 drivers/usb/core/driver.c:396 really_probe+0x1fd/0xd10 drivers/base/dd.c:576 driver_probe_device+0x21a/0x3b0 drivers/base/dd.c:763 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:431 __device_attach+0x1db/0x410 drivers/base/dd.c:938 bus_probe_device+0x19d/0x250 drivers/base/bus.c:491 device_add+0x9f0/0x1d60 drivers/base/core.c:3324 usb_set_configuration+0x9fc/0x1750 drivers/usb/core/message.c:2164 usb_generic_driver_probe+0x74/0xa0 drivers/usb/core/generic.c:238 usb_probe_device+0x98/0x240 drivers/usb/core/driver.c:293 really_probe+0x1fd/0xd10 drivers/base/dd.c:576 driver_probe_device+0x21a/0x3b0 drivers/base/dd.c:763 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:431 __device_attach+0x1db/0x410 drivers/base/dd.c:938 bus_probe_device+0x19d/0x250 drivers/base/bus.c:491 device_add+0x9f0/0x1d60 drivers/base/core.c:3324 usb_new_device.cold+0x69a/0xee1 drivers/usb/core/hub.c:2556 hub_port_connect drivers/usb/core/hub.c:5276 [inline] hub_port_connect_change drivers/usb/core/hub.c:5416 [inline] port_event drivers/usb/core/hub.c:5562 [inline] hub_event+0x10a3/0x36d0 drivers/usb/core/hub.c:5644 process_one_work+0x84c/0x13b0 kernel/workqueue.c:2276 worker_thread+0x598/0xf80 kernel/workqueue.c:2422 kthread+0x36f/0x450 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 INFO: task kworker/0:2:2966 blocked for more than 144 seconds. Not tainted 5.13.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:2 state:D stack:24672 pid: 2966 ppid: 2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x8de/0x2390 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5285 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7d4/0x10c0 kernel/locking/mutex.c:1104 hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:478 chaoskey_probe+0x7a6/0xb50 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x274/0x6a0 drivers/usb/core/driver.c:396 really_probe+0x1fd/0xd10 drivers/base/dd.c:576 driver_probe_device+0x21a/0x3b0 drivers/base/dd.c:763 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:431 __device_attach+0x1db/0x410 drivers/base/dd.c:938 bus_probe_device+0x19d/0x250 drivers/base/bus.c:491 device_add+0x9f0/0x1d60 drivers/base/core.c:3324 usb_set_configuration+0x9fc/0x1750 drivers/usb/core/message.c:2164 usb_generic_driver_probe+0x74/0xa0 drivers/usb/core/generic.c:238 usb_probe_device+0x98/0x240 drivers/usb/core/driver.c:293 really_probe+0x1fd/0xd10 drivers/base/dd.c:576 driver_probe_device+0x21a/0x3b0 drivers/base/dd.c:763 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:431 __device_attach+0x1db/0x410 drivers/base/dd.c:938 bus_probe_device+0x19d/0x250 drivers/base/bus.c:491 device_add+0x9f0/0x1d60 drivers/base/core.c:3324 usb_new_device.cold+0x69a/0xee1 drivers/usb/core/hub.c:2556 hub_port_connect drivers/usb/core/hub.c:5276 [inline] hub_port_connect_change drivers/usb/core/hub.c:5416 [inline] port_event drivers/usb/core/hub.c:5562 [inline] hub_event+0x10a3/0x36d0 drivers/usb/core/hub.c:5644 process_one_work+0x84c/0x13b0 kernel/workqueue.c:2276 worker_thread+0x598/0xf80 kernel/workqueue.c:2422 kthread+0x36f/0x450 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 INFO: task kworker/0:4:8613 blocked for more than 145 seconds. Not tainted 5.13.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:4 state:D stack:25368 pid: 8613 ppid: 2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x8de/0x2390 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5285 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7d4/0x10c0 kernel/locking/mutex.c:1104 hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:478 chaoskey_probe+0x7a6/0xb50 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x274/0x6a0 drivers/usb/core/driver.c:396 really_probe+0x1fd/0xd10 drivers/base/dd.c:576 driver_probe_device+0x21a/0x3b0 drivers/base/dd.c:763 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:431 __device_attach+0x1db/0x410 drivers/base/dd.c:938 bus_probe_device+0x19d/0x250 drivers/base/bus.c:491 device_add+0x9f0/0x1d60 drivers/base/core.c:3324 usb_set_configuration+0x9fc/0x1750 drivers/usb/core/message.c:2164 usb_generic_driver_probe+0x74/0xa0 drivers/usb/core/generic.c:238 usb_probe_device+0x98/0x240 drivers/usb/core/driver.c:293 really_probe+0x1fd/0xd10 drivers/base/dd.c:576 driver_probe_device+0x21a/0x3b0 drivers/base/dd.c:763 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:431 __device_attach+0x1db/0x410 drivers/base/dd.c:938 bus_probe_device+0x19d/0x250 drivers/base/bus.c:491 device_add+0x9f0/0x1d60 drivers/base/core.c:3324 usb_new_device.cold+0x69a/0xee1 drivers/usb/core/hub.c:2556 hub_port_connect drivers/usb/core/hub.c:5276 [inline] hub_port_connect_change drivers/usb/core/hub.c:5416 [inline] port_event drivers/usb/core/hub.c:5562 [inline] hub_event+0x10a3/0x36d0 drivers/usb/core/hub.c:5644 process_one_work+0x84c/0x13b0 kernel/workqueue.c:2276 worker_thread+0x598/0xf80 kernel/workqueue.c:2422 kthread+0x36f/0x450 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 INFO: task kworker/1:5:10053 blocked for more than 145 seconds. Not tainted 5.13.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:5 state:D stack:25440 pid:10053 ppid: 2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x8de/0x2390 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5285 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7d4/0x10c0 kernel/locking/mutex.c:1104 hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:478 chaoskey_probe+0x7a6/0xb50 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x274/0x6a0 drivers/usb/core/driver.c:396 really_probe+0x1fd/0xd10 drivers/base/dd.c:576 driver_probe_device+0x21a/0x3b0 drivers/base/dd.c:763 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:431 __device_attach+0x1db/0x410 drivers/base/dd.c:938 bus_probe_device+0x19d/0x250 drivers/base/bus.c:491 device_add+0x9f0/0x1d60 drivers/base/core.c:3324 usb_set_configuration+0x9fc/0x1750 drivers/usb/core/message.c:2164 usb_generic_driver_probe+0x74/0xa0 drivers/usb/core/generic.c:238 usb_probe_device+0x98/0x240 drivers/usb/core/driver.c:293 really_probe+0x1fd/0xd10 drivers/base/dd.c:576 driver_probe_device+0x21a/0x3b0 drivers/base/dd.c:763 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:431 __device_attach+0x1db/0x410 drivers/base/dd.c:938 bus_probe_device+0x19d/0x250 drivers/base/bus.c:491 device_add+0x9f0/0x1d60 drivers/base/core.c:3324 usb_new_device.cold+0x69a/0xee1 drivers/usb/core/hub.c:2556 hub_port_connect drivers/usb/core/hub.c:5276 [inline] hub_port_connect_change drivers/usb/core/hub.c:5416 [inline] port_event drivers/usb/core/hub.c:5562 [inline] hub_event+0x10a3/0x36d0 drivers/usb/core/hub.c:5644 process_one_work+0x84c/0x13b0 kernel/workqueue.c:2276 worker_thread+0x598/0xf80 kernel/workqueue.c:2422 kthread+0x36f/0x450 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 INFO: task kworker/1:7:10060 blocked for more than 146 seconds. Not tainted 5.13.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:7 state:D stack:25144 pid:10060 ppid: 2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x8de/0x2390 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5285 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7d4/0x10c0 kernel/locking/mutex.c:1104 hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:478 chaoskey_probe+0x7a6/0xb50 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x274/0x6a0 drivers/usb/core/driver.c:396 really_probe+0x1fd/0xd10 drivers/base/dd.c:576 driver_probe_device+0x21a/0x3b0 drivers/base/dd.c:763 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:431 __device_attach+0x1db/0x410 drivers/base/dd.c:938 bus_probe_device+0x19d/0x250 drivers/base/bus.c:491 device_add+0x9f0/0x1d60 drivers/base/core.c:3324 usb_set_configuration+0x9fc/0x1750 drivers/usb/core/message.c:2164 usb_generic_driver_probe+0x74/0xa0 drivers/usb/core/generic.c:238 usb_probe_device+0x98/0x240 drivers/usb/core/driver.c:293 really_probe+0x1fd/0xd10 drivers/base/dd.c:576 driver_probe_device+0x21a/0x3b0 drivers/base/dd.c:763 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:431 __device_attach+0x1db/0x410 drivers/base/dd.c:938 bus_probe_device+0x19d/0x250 drivers/base/bus.c:491 device_add+0x9f0/0x1d60 drivers/base/core.c:3324 usb_new_device.cold+0x69a/0xee1 drivers/usb/core/hub.c:2556 hub_port_connect drivers/usb/core/hub.c:5276 [inline] hub_port_connect_change drivers/usb/core/hub.c:5416 [inline] port_event drivers/usb/core/hub.c:5562 [inline] hub_event+0x10a3/0x36d0 drivers/usb/core/hub.c:5644 process_one_work+0x84c/0x13b0 kernel/workqueue.c:2276 worker_thread+0x598/0xf80 kernel/workqueue.c:2422 kthread+0x36f/0x450 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Showing all locks held in the system: 6 locks held by kworker/0:1/7: #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13b0 kernel/workqueue.c:2247 #1: ffffc90000cc7db0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13b0 kernel/workqueue.c:2251 #2: ffff88801bbb5220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #2: ffff88801bbb5220 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36d0 drivers/usb/core/hub.c:5590 #3: ffff88802cc6b220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #3: ffff88802cc6b220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:913 #4: ffff88803e2af1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #4: ffff88803e2af1a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:913 #5: ffffffff8b32e248 (rng_mutex){+.+.}-{3:3}, at: hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:478 6 locks held by kworker/1:0/19: #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13b0 kernel/workqueue.c:2247 #1: ffffc90000d97db0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13b0 kernel/workqueue.c:2251 #2: ffff88801bc38220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #2: ffff88801bc38220 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36d0 drivers/usb/core/hub.c:5590 #3: ffff88803f3cf220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #3: ffff88803f3cf220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:913 #4: ffff88802622a1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #4: ffff88802622a1a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:913 #5: ffffffff8b32e248 (rng_mutex){+.+.}-{3:3}, at: hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:478 1 lock held by khungtaskd/1664: #0: ffffffff8a96f440 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6333 6 locks held by kworker/0:2/2966: #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13b0 kernel/workqueue.c:2247 #1: ffffc9000273fdb0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13b0 kernel/workqueue.c:2251 #2: ffff88801bb7d220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #2: ffff88801bb7d220 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36d0 drivers/usb/core/hub.c:5590 #3: ffff888011e7f220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #3: ffff888011e7f220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:913 #4: ffff88803e2ad1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #4: ffff88803e2ad1a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:913 #5: ffffffff8b32e248 (rng_mutex){+.+.}-{3:3}, at: hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:478 1 lock held by in:imklog/8120: #0: ffff888024df6370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x9c/0xb0 fs/file.c:974 6 locks held by kworker/0:4/8613: #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13b0 kernel/workqueue.c:2247 #1: ffffc90001e5fdb0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13b0 kernel/workqueue.c:2251 #2: ffff88801bc88220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #2: ffff88801bc88220 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36d0 drivers/usb/core/hub.c:5590 #3: ffff88802c43c220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #3: ffff88802c43c220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:913 #4: ffff88803ecef1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #4: ffff88803ecef1a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:913 #5: ffffffff8b32e248 (rng_mutex){+.+.}-{3:3}, at: hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:478 6 locks held by kworker/1:5/10053: #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13b0 kernel/workqueue.c:2247 #1: ffffc9000ab1fdb0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13b0 kernel/workqueue.c:2251 #2: ffff88801bcc8220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #2: ffff88801bcc8220 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36d0 drivers/usb/core/hub.c:5590 #3: ffff88803dc5f220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #3: ffff88803dc5f220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:913 #4: ffff88803e7531a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #4: ffff88803e7531a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:913 #5: ffffffff8b32e248 (rng_mutex){+.+.}-{3:3}, at: hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:478 6 locks held by kworker/1:7/10060: #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff88801486b138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13b0 kernel/workqueue.c:2247 #1: ffffc9000ab5fdb0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13b0 kernel/workqueue.c:2251 #2: ffff888143c0d220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #2: ffff888143c0d220 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36d0 drivers/usb/core/hub.c:5590 #3: ffff88803dc5c220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #3: ffff88803dc5c220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:913 #4: ffff8880270631a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #4: ffff8880270631a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:913 #5: ffffffff8b32e248 (rng_mutex){+.+.}-{3:3}, at: hwrng_register+0x6b/0x500 drivers/char/hw_random/core.c:478 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1664 Comm: khungtaskd Not tainted 5.13.0-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:79 [inline] dump_stack+0x93/0xc2 lib/dump_stack.c:120 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:209 [inline] watchdog+0x956/0xc30 kernel/hung_task.c:294 kthread+0x36f/0x450 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 321 Comm: kworker/u4:6 Not tainted 5.13.0-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_read_lock_sched_held+0x0/0x70 kernel/rcu/update.c:120 Code: 41 5c 49 c1 ec 09 49 83 f4 01 41 83 e4 01 44 89 e0 41 5c c3 45 31 e4 44 89 e0 41 5c c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 <41> 54 41 bc 01 00 00 00 e8 d3 f8 ee 06 85 c0 75 06 44 89 e0 41 5c RSP: 0018:ffffc90001b3fbc0 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8151f511 RDX: fffffbfff18b0663 RSI: 0000000000000008 RDI: ffffffff8c583310 RBP: 1ffff92000367f7b R08: 0000000000000000 R09: ffffffff8c583317 R10: fffffbfff18b0662 R11: 0000000000000000 R12: ffffffff8a96f440 R13: ffff888012344c00 R14: ffff888012345658 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7250b71000 CR3: 000000002492b000 CR4: 00000000001506f0 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+0x5be/0x710 kernel/locking/lockdep.c:5523 rcu_lock_release include/linux/rcupdate.h:272 [inline] rcu_read_unlock include/linux/rcupdate.h:711 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x602/0xcc0 net/batman-adv/network-coding.c:715 process_one_work+0x84c/0x13b0 kernel/workqueue.c:2276 worker_thread+0x598/0xf80 kernel/workqueue.c:2422 kthread+0x36f/0x450 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294