block nbd4: shutting down sockets block nbd5: Device being setup by another task block nbd5: shutting down sockets block nbd0: Device being setup by another task block nbd0: shutting down sockets INFO: task syz-executor.3:7839 blocked for more than 140 seconds. Not tainted 4.19.158-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D27752 7839 6592 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x6e1/0xe00 kernel/time/timer.c:1794 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:1268 [inline] __nbd_ioctl drivers/block/nbd.c:1339 [inline] nbd_ioctl+0x2c8/0xb30 drivers/block/nbd.c:1379 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x7fc/0x17a0 block/ioctl.c:601 block_ioctl+0xd7/0x130 fs/block_dev.c:1906 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: 0033:0x45c749 Code: 48 83 ec 10 48 89 6c 24 08 48 8d 6c 24 08 48 8b 42 08 48 8b 40 08 48 89 04 24 e8 62 a3 fc ff 48 8b 6c 24 08 48 83 c4 10 c3 e8 36 00 00 eb c1 cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 72 RSP: 002b:00007f8c92365c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f8c923666d4 RCX: 000000000045c749 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003fb R14: 00000000004c6889 R15: 000000000076bf2c INFO: task syz-executor.1:7911 blocked for more than 140 seconds. Not tainted 4.19.158-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D27880 7911 6616 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x6e1/0xe00 kernel/time/timer.c:1794 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:1268 [inline] __nbd_ioctl drivers/block/nbd.c:1339 [inline] nbd_ioctl+0x2c8/0xb30 drivers/block/nbd.c:1379 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x7fc/0x17a0 block/ioctl.c:601 block_ioctl+0xd7/0x130 fs/block_dev.c:1906 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: 0033:0x45c749 Code: 48 83 ec 10 48 89 6c 24 08 48 8d 6c 24 08 48 8b 42 08 48 8b 40 08 48 89 04 24 e8 62 a3 fc ff 48 8b 6c 24 08 48 83 c4 10 c3 e8 36 00 00 eb c1 cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 72 RSP: 002b:00007f248d649c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f248d64a6d4 RCX: 000000000045c749 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003fb R14: 00000000004c6889 R15: 000000000076bf2c INFO: task syz-executor.2:7930 blocked for more than 140 seconds. Not tainted 4.19.158-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28072 7930 6591 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x6e1/0xe00 kernel/time/timer.c:1794 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:1268 [inline] __nbd_ioctl drivers/block/nbd.c:1339 [inline] nbd_ioctl+0x2c8/0xb30 drivers/block/nbd.c:1379 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x7fc/0x17a0 block/ioctl.c:601 block_ioctl+0xd7/0x130 fs/block_dev.c:1906 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: 0033:0x45c749 Code: Bad RIP value. RSP: 002b:00007fa34ea81c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa34ea826d4 RCX: 000000000045c749 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003fb R14: 00000000004c6889 R15: 000000000076bf2c INFO: task syz-executor.5:7940 blocked for more than 140 seconds. Not tainted 4.19.158-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28136 7940 6595 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x6e1/0xe00 kernel/time/timer.c:1794 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:1268 [inline] __nbd_ioctl drivers/block/nbd.c:1339 [inline] nbd_ioctl+0x2c8/0xb30 drivers/block/nbd.c:1379 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x7fc/0x17a0 block/ioctl.c:601 block_ioctl+0xd7/0x130 fs/block_dev.c:1906 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: 0033:0x45c749 Code: Bad RIP value. RSP: 002b:00007fe7fce21c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe7fce226d4 RCX: 000000000045c749 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003fb R14: 00000000004c6889 R15: 000000000076bf2c INFO: task syz-executor.4:7939 blocked for more than 140 seconds. Not tainted 4.19.158-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D27960 7939 6596 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x6e1/0xe00 kernel/time/timer.c:1794 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:1268 [inline] __nbd_ioctl drivers/block/nbd.c:1339 [inline] nbd_ioctl+0x2c8/0xb30 drivers/block/nbd.c:1379 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x7fc/0x17a0 block/ioctl.c:601 block_ioctl+0xd7/0x130 fs/block_dev.c:1906 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: 0033:0x45c749 Code: Bad RIP value. RSP: 002b:00007fcab6168c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fcab61696d4 RCX: 000000000045c749 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003fb R14: 00000000004c6889 R15: 000000000076bf2c INFO: task syz-executor.0:7957 blocked for more than 140 seconds. Not tainted 4.19.158-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D27800 7957 6601 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x6e1/0xe00 kernel/time/timer.c:1794 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:1268 [inline] __nbd_ioctl drivers/block/nbd.c:1339 [inline] nbd_ioctl+0x2c8/0xb30 drivers/block/nbd.c:1379 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x7fc/0x17a0 block/ioctl.c:601 block_ioctl+0xd7/0x130 fs/block_dev.c:1906 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: 0033:0x45c749 Code: Bad RIP value. RSP: 002b:00007f937c022c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f937c0236d4 RCX: 000000000045c749 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003fb R14: 00000000004c6889 R15: 000000000076bf2c Showing all locks held in the system: 1 lock held by khungtaskd/1069: #0: 000000001ff7eadc (rcu_read_lock){....}, at: debug_show_all_locks+0x5b/0x27a kernel/locking/lockdep.c:4442 2 locks held by kworker/u5:0/1221: #0: 00000000b35fb88f ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 00000000b35fb88f ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000b35fb88f ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000b35fb88f ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000b35fb88f ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000b35fb88f ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000b35fb88f ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: process_one_work+0x762/0x1670 kernel/workqueue.c:2126 #1: 00000000d1d1e2ca ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x792/0x1670 kernel/workqueue.c:2130 1 lock held by in:imklog/6101: #0: 00000000ed6b3e57 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xa7/0xd0 fs/file.c:767 2 locks held by kworker/u5:1/7847: #0: 00000000b42b7778 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 00000000b42b7778 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000b42b7778 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000b42b7778 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000b42b7778 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000b42b7778 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000b42b7778 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: process_one_work+0x762/0x1670 kernel/workqueue.c:2126 #1: 00000000b31448eb ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x792/0x1670 kernel/workqueue.c:2130 2 locks held by kworker/u5:2/7918: #0: 00000000c279299a ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 00000000c279299a ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000c279299a ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000c279299a ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000c279299a ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000c279299a ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000c279299a ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: process_one_work+0x762/0x1670 kernel/workqueue.c:2126 #1: 00000000fbc76441 ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x792/0x1670 kernel/workqueue.c:2130 2 locks held by kworker/u5:3/7936: #0: 0000000007c7ebfc ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 0000000007c7ebfc ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000007c7ebfc ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000007c7ebfc ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 0000000007c7ebfc ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000007c7ebfc ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000007c7ebfc ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: process_one_work+0x762/0x1670 kernel/workqueue.c:2126 #1: 00000000033e3195 ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x792/0x1670 kernel/workqueue.c:2130 2 locks held by kworker/u5:4/7945: #0: 0000000015ae5ad5 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 0000000015ae5ad5 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000015ae5ad5 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000015ae5ad5 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 0000000015ae5ad5 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000015ae5ad5 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000015ae5ad5 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: process_one_work+0x762/0x1670 kernel/workqueue.c:2126 #1: 000000009220872e ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x792/0x1670 kernel/workqueue.c:2130 2 locks held by kworker/u5:5/7949: #0: 00000000797cb4ce ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 00000000797cb4ce ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000797cb4ce ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000797cb4ce ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000797cb4ce ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000797cb4ce ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000797cb4ce ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: process_one_work+0x762/0x1670 kernel/workqueue.c:2126 #1: 000000005220deb1 ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x792/0x1670 kernel/workqueue.c:2130 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1069 Comm: khungtaskd Not tainted 4.19.158-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+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 47 Comm: kworker/u4:2 Not tainted 4.19.158-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+0x22/0x50 kernel/rcu/tree_plugin.h:405 Code: 0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 e5 53 65 48 8b 1c 25 40 ee 01 00 48 8d bb 70 03 00 00 48 89 fa <48> c1 ea 03 0f b6 04 02 84 c0 74 04 3c 03 7e 0a 83 83 70 03 00 00 RSP: 0018:ffff8880b56dfcf8 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffff8880b56c6480 RCX: 1ffff11016ad8d9f RDX: ffff8880b56c67f0 RSI: 0000000000000003 RDI: ffff8880b56c67f0 RBP: ffff8880b56dfd00 R08: 0000000000000000 R09: ffffed10174e4732 R10: ffffed10174e4732 R11: ffff8880ba723993 R12: ffff8880abb0d000 R13: 00000000000000da R14: ffff8880b13b51d0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880ba700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff48159b000 CR3: 00000000a421f000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock include/linux/rcupdate.h:625 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:419 [inline] batadv_nc_worker+0xcc/0x630 net/batman-adv/network-coding.c:730 process_one_work+0x830/0x1670 kernel/workqueue.c:2155 worker_thread+0x85/0xb60 kernel/workqueue.c:2298 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415