block nbd0: Device being setup by another task block nbd0: shutting down sockets block nbd3: shutting down sockets NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 INFO: task syz-executor.2:7821 blocked for more than 140 seconds. Not tainted 4.19.119-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D27528 7821 6571 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x6d5/0xda0 kernel/time/timer.c:1782 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x282/0x460 kernel/sched/completion.c:136 flush_workqueue+0x35d/0x13c0 kernel/workqueue.c:2715 nbd_start_device_ioctl drivers/block/nbd.c:1262 [inline] __nbd_ioctl drivers/block/nbd.c:1333 [inline] nbd_ioctl+0x2c8/0xb20 drivers/block/nbd.c:1373 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x7ae/0x16e0 block/ioctl.c:601 block_ioctl+0xd7/0x130 fs/block_dev.c:1894 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x196/0x10c0 fs/ioctl.c:688 ksys_ioctl+0x62/0x90 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:710 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c6c9 Code: Bad RIP value. RSP: 002b:00007fa6ffe73c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa6ffe746d4 RCX: 000000000045c6c9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003fb R14: 00000000004c6809 R15: 000000000076bf2c INFO: task syz-executor.4:7861 blocked for more than 140 seconds. Not tainted 4.19.119-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28136 7861 6582 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x6d5/0xda0 kernel/time/timer.c:1782 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x282/0x460 kernel/sched/completion.c:136 flush_workqueue+0x35d/0x13c0 kernel/workqueue.c:2715 nbd_start_device_ioctl drivers/block/nbd.c:1262 [inline] __nbd_ioctl drivers/block/nbd.c:1333 [inline] nbd_ioctl+0x2c8/0xb20 drivers/block/nbd.c:1373 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x7ae/0x16e0 block/ioctl.c:601 block_ioctl+0xd7/0x130 fs/block_dev.c:1894 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x196/0x10c0 fs/ioctl.c:688 ksys_ioctl+0x62/0x90 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:710 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c6c9 Code: Bad RIP value. RSP: 002b:00007f696e036c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f696e0376d4 RCX: 000000000045c6c9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003fb R14: 00000000004c6809 R15: 000000000076bf2c INFO: task syz-executor.1:7910 blocked for more than 140 seconds. Not tainted 4.19.119-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28136 7910 6591 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x6d5/0xda0 kernel/time/timer.c:1782 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x282/0x460 kernel/sched/completion.c:136 flush_workqueue+0x35d/0x13c0 kernel/workqueue.c:2715 nbd_start_device_ioctl drivers/block/nbd.c:1262 [inline] __nbd_ioctl drivers/block/nbd.c:1333 [inline] nbd_ioctl+0x2c8/0xb20 drivers/block/nbd.c:1373 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x7ae/0x16e0 block/ioctl.c:601 block_ioctl+0xd7/0x130 fs/block_dev.c:1894 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x196/0x10c0 fs/ioctl.c:688 ksys_ioctl+0x62/0x90 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:710 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c6c9 Code: Bad RIP value. RSP: 002b:00007f87c7750c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f87c77516d4 RCX: 000000000045c6c9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003fb R14: 00000000004c6809 R15: 000000000076bf2c INFO: task syz-executor.5:7917 blocked for more than 140 seconds. Not tainted 4.19.119-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28136 7917 6579 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x6d5/0xda0 kernel/time/timer.c:1782 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x282/0x460 kernel/sched/completion.c:136 flush_workqueue+0x35d/0x13c0 kernel/workqueue.c:2715 nbd_start_device_ioctl drivers/block/nbd.c:1262 [inline] __nbd_ioctl drivers/block/nbd.c:1333 [inline] nbd_ioctl+0x2c8/0xb20 drivers/block/nbd.c:1373 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x7ae/0x16e0 block/ioctl.c:601 block_ioctl+0xd7/0x130 fs/block_dev.c:1894 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x196/0x10c0 fs/ioctl.c:688 ksys_ioctl+0x62/0x90 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:710 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c6c9 Code: Bad RIP value. RSP: 002b:00007f3c4c137c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f3c4c1386d4 RCX: 000000000045c6c9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003fb R14: 00000000004c6809 R15: 000000000076bf2c INFO: task syz-executor.0:7921 blocked for more than 140 seconds. Not tainted 4.19.119-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28136 7921 6575 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x6d5/0xda0 kernel/time/timer.c:1782 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x282/0x460 kernel/sched/completion.c:136 flush_workqueue+0x35d/0x13c0 kernel/workqueue.c:2715 nbd_start_device_ioctl drivers/block/nbd.c:1262 [inline] __nbd_ioctl drivers/block/nbd.c:1333 [inline] nbd_ioctl+0x2c8/0xb20 drivers/block/nbd.c:1373 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x7ae/0x16e0 block/ioctl.c:601 block_ioctl+0xd7/0x130 fs/block_dev.c:1894 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x196/0x10c0 fs/ioctl.c:688 ksys_ioctl+0x62/0x90 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:710 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c6c9 Code: Bad RIP value. RSP: 002b:00007ff7860c3c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff7860c46d4 RCX: 000000000045c6c9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003fb R14: 00000000004c6809 R15: 000000000076bf2c INFO: task syz-executor.3:7931 blocked for more than 140 seconds. Not tainted 4.19.119-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28136 7931 6573 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x6d5/0xda0 kernel/time/timer.c:1782 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x282/0x460 kernel/sched/completion.c:136 flush_workqueue+0x35d/0x13c0 kernel/workqueue.c:2715 nbd_start_device_ioctl drivers/block/nbd.c:1262 [inline] __nbd_ioctl drivers/block/nbd.c:1333 [inline] nbd_ioctl+0x2c8/0xb20 drivers/block/nbd.c:1373 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x7ae/0x16e0 block/ioctl.c:601 block_ioctl+0xd7/0x130 fs/block_dev.c:1894 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x196/0x10c0 fs/ioctl.c:688 ksys_ioctl+0x62/0x90 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:710 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c6c9 Code: Bad RIP value. RSP: 002b:00007fa3e89d2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa3e89d36d4 RCX: 000000000045c6c9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003fb R14: 00000000004c6809 R15: 000000000076bf2c Showing all locks held in the system: 1 lock held by khungtaskd/1083: #0: 000000009298b6f9 (rcu_read_lock){....}, at: debug_show_all_locks+0x5b/0x27a kernel/locking/lockdep.c:4442 2 locks held by kworker/u5:0/1219: #0: 00000000951415b0 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 00000000951415b0 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000951415b0 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000951415b0 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000951415b0 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000951415b0 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000951415b0 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: process_one_work+0x762/0x1670 kernel/workqueue.c:2126 #1: 000000005e550b7b ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x792/0x1670 kernel/workqueue.c:2130 1 lock held by in:imklog/6125: #0: 000000002ccd27de (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xa7/0xd0 fs/file.c:767 2 locks held by kworker/u5:1/7823: #0: 000000005debfa56 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 000000005debfa56 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000005debfa56 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000005debfa56 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 000000005debfa56 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000005debfa56 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000005debfa56 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: process_one_work+0x762/0x1670 kernel/workqueue.c:2126 #1: 00000000f7e32809 ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x792/0x1670 kernel/workqueue.c:2130 2 locks held by kworker/u5:2/7870: #0: 0000000036248559 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 0000000036248559 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000036248559 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000036248559 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 0000000036248559 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000036248559 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000036248559 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: process_one_work+0x762/0x1670 kernel/workqueue.c:2126 #1: 00000000e8381f2f ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x792/0x1670 kernel/workqueue.c:2130 2 locks held by kworker/u5:3/7923: #0: 000000003ccc8022 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 000000003ccc8022 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000003ccc8022 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000003ccc8022 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 000000003ccc8022 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000003ccc8022 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000003ccc8022 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: process_one_work+0x762/0x1670 kernel/workqueue.c:2126 #1: 00000000dbd8acea ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x792/0x1670 kernel/workqueue.c:2130 2 locks held by kworker/u5:4/7927: #0: 0000000021177970 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 0000000021177970 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000021177970 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000021177970 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 0000000021177970 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000021177970 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000021177970 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: process_one_work+0x762/0x1670 kernel/workqueue.c:2126 #1: 000000004b80c349 ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x792/0x1670 kernel/workqueue.c:2130 2 locks held by kworker/u5:5/7932: #0: 000000002713f253 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 000000002713f253 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000002713f253 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000002713f253 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 000000002713f253 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000002713f253 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000002713f253 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: process_one_work+0x762/0x1670 kernel/workqueue.c:2126 #1: 00000000b728b5f1 ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x792/0x1670 kernel/workqueue.c:2130 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1083 Comm: khungtaskd Not tainted 4.19.119-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+0x123/0x177 lib/dump_stack.c:118 nmi_cpu_backtrace.cold.4+0x3e/0x76 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0xe6/0x11a lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x5c3/0xb40 kernel/hung_task.c:287 kthread+0x324/0x3e0 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6126 Comm: rs:main Q:Reg Not tainted 4.19.119-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:rcu_lockdep_current_cpu_online+0x32/0x1d0 kernel/rcu/tree.c:1087 Code: 41 55 41 54 53 48 83 ec 08 65 8b 05 88 d5 b0 7e a9 00 00 10 00 75 0a 8b 05 eb 96 d1 07 85 c0 75 14 b8 01 00 00 00 48 83 c4 08 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 bf 01 00 00 00 e8 f9 e4 f0 ff 48 RSP: 0018:ffff88808909f710 EFLAGS: 00000092 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000004 RSI: ffffffff87678080 RDI: ffffffff8a186960 RBP: ffff88808909f738 R08: ffffed1015d44733 R09: ffffed1015d44732 R10: ffffed1015d44732 R11: ffff8880aea23993 R12: dffffc0000000000 R13: ffffffff882a4f00 R14: ffffffff8858eb00 R15: ffffffff8858eb00 FS: 00007fc33fb3f700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f83ba258000 CR3: 0000000087d14000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock_held+0x90/0xc0 kernel/rcu/update.c:285 test_idle_cores kernel/sched/fair.c:6041 [inline] __update_idle_core+0x2b6/0x3f0 kernel/sched/fair.c:6061 update_idle_core kernel/sched/sched.h:940 [inline] pick_next_task_idle+0xc6/0x100 kernel/sched/idle.c:396 pick_next_task kernel/sched/core.c:3367 [inline] __schedule+0x13e2/0x1c10 kernel/sched/core.c:3489 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 freezable_schedule include/linux/freezer.h:172 [inline] futex_wait_queue_me+0x2ec/0x5b0 kernel/futex.c:2627 futex_wait+0x256/0x530 kernel/futex.c:2742 do_futex+0x5d2/0x1910 kernel/futex.c:3709 __do_sys_futex kernel/futex.c:3770 [inline] __se_sys_futex kernel/futex.c:3738 [inline] __x64_sys_futex+0x1cb/0x3a0 kernel/futex.c:3738 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fc34258017f Code: 30 83 f8 20 75 15 be 8b 00 00 00 b8 ca 00 00 00 0f 05 83 f8 00 41 0f 94 c0 eb 0f be 80 00 00 00 45 30 c0 b8 ca 00 00 00 0f 05 <8b> 3c 24 e8 49 2d 00 00 48 8b 7c 24 08 be 01 00 00 00 31 c0 f0 0f RSP: 002b:00007fc33fb3ec70 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc34258017f RDX: 0000000000000615 RSI: 0000000000000080 RDI: 00005631f840628c RBP: 00005631f8406288 R08: 00005631f8406000 R09: 000000000000030a R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc33fb3ecd0 R13: 0000000000000000 R14: 00005631f7c0e290 R15: 0000000000000000