INFO: task syz-executor.0:10163 blocked for more than 143 seconds. Not tainted 5.12.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:27608 pid:10163 ppid: 8796 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0x8d9/0x2160 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5211 __mutex_lock_common kernel/locking/mutex.c:1026 [inline] __mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1096 misc_open+0x50/0x410 drivers/char/misc.c:107 chrdev_open+0x20f/0x650 fs/char_dev.c:414 do_dentry_open+0x42a/0xfb0 fs/open.c:826 do_open fs/namei.c:3365 [inline] path_openat+0x9ee/0x22b0 fs/namei.c:3498 do_filp_open+0x16d/0x390 fs/namei.c:3525 do_sys_openat2+0x11e/0x360 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_openat fs/open.c:1219 [inline] __se_sys_openat fs/open.c:1214 [inline] __x64_sys_openat+0x11b/0x1d0 fs/open.c:1214 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4190f4 RSP: 002b:00007f7c2e975040 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 00000000004190f4 RDX: 0000000000000002 RSI: 00000000004af0ab RDI: 00000000ffffff9c RBP: 00000000004af0ab R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000020001940 R15: 0000000000022000 INFO: task syz-executor.2:10181 blocked for more than 143 seconds. Not tainted 5.12.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:27608 pid:10181 ppid: 8802 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0x8d9/0x2160 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5211 __mutex_lock_common kernel/locking/mutex.c:1026 [inline] __mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1096 misc_open+0x50/0x410 drivers/char/misc.c:107 chrdev_open+0x20f/0x650 fs/char_dev.c:414 do_dentry_open+0x42a/0xfb0 fs/open.c:826 do_open fs/namei.c:3365 [inline] path_openat+0x9ee/0x22b0 fs/namei.c:3498 do_filp_open+0x16d/0x390 fs/namei.c:3525 do_sys_openat2+0x11e/0x360 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_openat fs/open.c:1219 [inline] __se_sys_openat fs/open.c:1214 [inline] __x64_sys_openat+0x11b/0x1d0 fs/open.c:1214 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x465b09 RSP: 002b:00007f958c3f9188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000000020601 RSI: 00000000200003c0 RDI: ffffffffffffff9c RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffebb3312bf R14: 00007f958c3f9300 R15: 0000000000022000 INFO: task syz-executor.3:10201 blocked for more than 143 seconds. Not tainted 5.12.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:27608 pid:10201 ppid: 8794 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0x8d9/0x2160 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5211 __mutex_lock_common kernel/locking/mutex.c:1026 [inline] __mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1096 misc_open+0x50/0x410 drivers/char/misc.c:107 chrdev_open+0x20f/0x650 fs/char_dev.c:414 do_dentry_open+0x42a/0xfb0 fs/open.c:826 do_open fs/namei.c:3365 [inline] path_openat+0x9ee/0x22b0 fs/namei.c:3498 do_filp_open+0x16d/0x390 fs/namei.c:3525 do_sys_openat2+0x11e/0x360 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_openat fs/open.c:1219 [inline] __se_sys_openat fs/open.c:1214 [inline] __x64_sys_openat+0x11b/0x1d0 fs/open.c:1214 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x465b09 RSP: 002b:00007f8086247188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000000020601 RSI: 00000000200003c0 RDI: ffffffffffffff9c RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffe8766b83f R14: 00007f8086247300 R15: 0000000000022000 INFO: task syz-executor.1:10203 blocked for more than 144 seconds. Not tainted 5.12.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.1 state:D stack:27608 pid:10203 ppid: 8799 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0x8d9/0x2160 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5211 __mutex_lock_common kernel/locking/mutex.c:1026 [inline] __mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1096 misc_open+0x50/0x410 drivers/char/misc.c:107 chrdev_open+0x20f/0x650 fs/char_dev.c:414 do_dentry_open+0x42a/0xfb0 fs/open.c:826 do_open fs/namei.c:3365 [inline] path_openat+0x9ee/0x22b0 fs/namei.c:3498 do_filp_open+0x16d/0x390 fs/namei.c:3525 do_sys_openat2+0x11e/0x360 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_openat fs/open.c:1219 [inline] __se_sys_openat fs/open.c:1214 [inline] __x64_sys_openat+0x11b/0x1d0 fs/open.c:1214 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4190f4 RSP: 002b:00007f3cd16ac040 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004190f4 RDX: 0000000000000002 RSI: 00000000004af0ab RDI: 00000000ffffff9c RBP: 00000000004af0ab R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000020000440 R15: 0000000000022000 INFO: task syz-executor.5:10262 blocked for more than 144 seconds. Not tainted 5.12.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.5 state:D stack:27296 pid:10262 ppid: 8801 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0x8d9/0x2160 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5211 __mutex_lock_common kernel/locking/mutex.c:1026 [inline] __mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1096 misc_open+0x50/0x410 drivers/char/misc.c:107 chrdev_open+0x20f/0x650 fs/char_dev.c:414 do_dentry_open+0x42a/0xfb0 fs/open.c:826 do_open fs/namei.c:3365 [inline] path_openat+0x9ee/0x22b0 fs/namei.c:3498 do_filp_open+0x16d/0x390 fs/namei.c:3525 do_sys_openat2+0x11e/0x360 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_openat fs/open.c:1219 [inline] __se_sys_openat fs/open.c:1214 [inline] __x64_sys_openat+0x11b/0x1d0 fs/open.c:1214 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4190f4 RSP: 002b:00007f410ca2e040 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004190f4 RDX: 0000000000000002 RSI: 00000000004af0ab RDI: 00000000ffffff9c RBP: 00000000004af0ab R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000020000440 R15: 0000000000022000 INFO: task syz-executor.4:10265 blocked for more than 144 seconds. Not tainted 5.12.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:27608 pid:10265 ppid: 8797 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0x8d9/0x2160 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5211 __mutex_lock_common kernel/locking/mutex.c:1026 [inline] __mutex_lock+0x81f/0x1120 kernel/locking/mutex.c:1096 misc_open+0x50/0x410 drivers/char/misc.c:107 chrdev_open+0x20f/0x650 fs/char_dev.c:414 do_dentry_open+0x42a/0xfb0 fs/open.c:826 do_open fs/namei.c:3365 [inline] path_openat+0x9ee/0x22b0 fs/namei.c:3498 do_filp_open+0x16d/0x390 fs/namei.c:3525 do_sys_openat2+0x11e/0x360 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_openat fs/open.c:1219 [inline] __se_sys_openat fs/open.c:1214 [inline] __x64_sys_openat+0x11b/0x1d0 fs/open.c:1214 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4190f4 RSP: 002b:00007fb7703c4040 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004190f4 RDX: 0000000000000002 RSI: 00000000004af0ab RDI: 00000000ffffff9c RBP: 00000000004af0ab R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000020000440 R15: 0000000000022000 Showing all locks held in the system: 5 locks held by kworker/0:1/7: #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13b0 kernel/workqueue.c:2246 #1: ffffc90000cc7db0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13b0 kernel/workqueue.c:2250 #2: ffff888144260218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:740 [inline] #2: ffff888144260218 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36b0 drivers/usb/core/hub.c:5537 #3: ffff88803b329218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:740 [inline] #3: ffff88803b329218 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x400 drivers/base/dd.c:889 #4: ffff88803b3591a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:740 [inline] #4: ffff88803b3591a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x400 drivers/base/dd.c:889 1 lock held by khungtaskd/1657: #0: ffffffff8a96a6c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6327 5 locks held by kworker/1:2/4340: #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13b0 kernel/workqueue.c:2246 #1: ffffc90009d6fdb0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13b0 kernel/workqueue.c:2250 #2: ffff888144220218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:740 [inline] #2: ffff888144220218 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36b0 drivers/usb/core/hub.c:5537 #3: ffff88802e9b8218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:740 [inline] #3: ffff88802e9b8218 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x400 drivers/base/dd.c:889 #4: ffff8880119ba1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:740 [inline] #4: ffff8880119ba1a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x400 drivers/base/dd.c:889 1 lock held by in:imklog/8147: #0: ffff888025a4d4f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x9c/0xb0 fs/file.c:961 5 locks held by kworker/0:7/10108: #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888013edf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13b0 kernel/workqueue.c:2246 #1: ffffc9000a5dfdb0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13b0 kernel/workqueue.c:2250 #2: ffff888144248218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:740 [inline] #2: ffff888144248218 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36b0 drivers/usb/core/hub.c:5537 #3: ffff88803b328218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:740 [inline] #3: ffff88803b328218 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x400 drivers/base/dd.c:889 #4: ffff88803b35e1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:740 [inline] #4: ffff88803b35e1a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x400 drivers/base/dd.c:889 2 locks held by syz-executor.0/10159: #0: ffffffff8b3206c8 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x50/0x410 drivers/char/misc.c:107 #1: ffffffff8a83bda8 (system_transition_mutex){+.+.}-{3:3}, at: snapshot_open+0x1c/0x210 kernel/power/user.c:54 1 lock held by syz-executor.0/10163: #0: ffffffff8b3206c8 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x50/0x410 drivers/char/misc.c:107 1 lock held by syz-executor.2/10181: #0: ffffffff8b3206c8 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x50/0x410 drivers/char/misc.c:107 1 lock held by syz-executor.3/10201: #0: ffffffff8b3206c8 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x50/0x410 drivers/char/misc.c:107 1 lock held by syz-executor.1/10203: #0: ffffffff8b3206c8 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x50/0x410 drivers/char/misc.c:107 1 lock held by syz-executor.5/10262: #0: ffffffff8b3206c8 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x50/0x410 drivers/char/misc.c:107 1 lock held by syz-executor.4/10265: #0: ffffffff8b3206c8 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x50/0x410 drivers/char/misc.c:107 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1657 Comm: khungtaskd Not tainted 5.12.0-rc5-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:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10081 Comm: kworker/1:7 Not tainted 5.12.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events nsim_dev_trap_report_work RIP: 0010:lock_acquire+0x79/0x730 kernel/locking/lockdep.c:5478 Code: 24 20 b0 31 51 81 c7 00 f1 f1 f1 f1 c7 40 04 f1 f1 00 00 c7 40 08 00 00 00 f3 c7 40 0c f3 f3 f3 f3 65 48 8b 04 25 28 00 00 00 <48> 89 84 24 a8 00 00 00 31 c0 0f 1f 44 00 00 65 8b 15 29 63 b0 7e RSP: 0018:ffffc9000a55fa20 EFLAGS: 00000082 RAX: 0ea520830d6d9000 RBX: 1ffff920014abf46 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88800f1a5b60 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: ffffed100305b804 R11: 00000000a9f99689 R12: 0000000000000000 R13: ffff88800f1a5b60 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f15a4916028 CR3: 0000000013182000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 _crng_backtrack_protect+0x4d/0x150 drivers/char/random.c:1045 crng_backtrack_protect drivers/char/random.c:1063 [inline] _get_random_bytes+0x1f7/0x540 drivers/char/random.c:1551 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:540 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:570 [inline] nsim_dev_trap_report_work+0x702/0xb50 drivers/net/netdevsim/dev.c:611 process_one_work+0x84c/0x13b0 kernel/workqueue.c:2275 worker_thread+0x598/0xf80 kernel/workqueue.c:2421 kthread+0x36f/0x450 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294