INFO: task syz-executor.0:12344 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D27384 12344 8131 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x92d/0xfe0 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+0x29c/0x470 kernel/sched/completion.c:115 flush_workqueue+0x40b/0x13e0 kernel/workqueue.c:2713 nbd_start_device_ioctl drivers/block/nbd.c:1276 [inline] __nbd_ioctl drivers/block/nbd.c:1347 [inline] nbd_ioctl+0x75b/0xbe0 drivers/block/nbd.c:1387 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x5cb/0x1a80 block/ioctl.c:601 block_ioctl+0xe9/0x130 fs/block_dev.c:1906 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f62d53db0d9 Code: Bad RIP value. RSP: 002b:00007f62d394d168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f62d54faf80 RCX: 00007f62d53db0d9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 00007f62d5436ae9 R08: 0000000000000000 R09: 0000000000000000 tc_dump_action: action bad kind R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffddb9d286f R14: 00007f62d394d300 R15: 0000000000022000 Showing all locks held in the system: 3 locks held by kworker/0:0/5: #0: 00000000bbfa4fc5 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1826 [inline] #0: 00000000bbfa4fc5 (&rq->lock){-.-.}, at: __schedule+0x1f9/0x2040 kernel/sched/core.c:3455 #1: 000000009c5f7cf5 (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:428 [inline] #1: 000000009c5f7cf5 (rcu_read_lock){....}, at: update_curr+0x2c3/0x870 kernel/sched/fair.c:857 #2: 000000002d6534b7 (&base->lock){-.-.}, at: lock_timer_base+0x55/0x1b0 kernel/time/timer.c:950 1 lock held by khungtaskd/1571: #0: 000000009c5f7cf5 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by in:imklog/7780: #0: 00000000ee7d3688 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 2 locks held by kworker/u5:3/8160: #0: 0000000002bad2d9 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 0000000090c50bdd ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 3 locks held by kworker/u4:5/8817: 1 lock held by syz-executor.3/20660: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1571 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 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: 20588 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:timerqueue_add+0xd1/0x270 lib/timerqueue.c:50 Code: be 01 00 00 00 48 bd 00 00 00 00 00 fc ff df eb 2a e8 13 8f 72 f9 4c 8d 7b 10 e8 0a 8f 72 f9 4c 89 fa 48 c1 ea 03 80 3c 2a 00 <0f> 85 24 01 00 00 49 8b 17 48 85 d2 74 3f 48 89 d3 e8 e9 8e 72 f9 RSP: 0000:ffff8880ba107d88 EFLAGS: 00000046 RAX: ffff88808f554080 RBX: ffff8880b253fdd0 RCX: ffffffff87eff6ab RDX: 1ffff110164a7fbc RSI: ffffffff87eff666 RDI: 0000000000000006 RBP: dffffc0000000000 R08: 0000000000000000 R09: 000000be31abcd27 R10: 0000000000000006 R11: ffffffff8c66505b R12: 000000be31abcd27 R13: ffff88804415ae18 R14: 0000000000000001 R15: ffff8880b253fde0 FS: 00007fcce84be700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5af1ea8000 CR3: 00000000b0231000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: enqueue_hrtimer+0x139/0x3d0 kernel/time/hrtimer.c:979 __run_hrtimer kernel/time/hrtimer.c:1480 [inline] __hrtimer_run_queues+0xae6/0xe60 kernel/time/hrtimer.c:1527 hrtimer_interrupt+0x326/0x9e0 kernel/time/hrtimer.c:1585 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1071 [inline] smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1096 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0033:0x7fcce9ee9005 Code: d3 83 e8 01 44 01 ca 01 c9 44 8d 0c 12 41 83 c0 01 4c 89 ea 85 c0 75 c9 44 89 d0 44 29 c0 74 55 48 8b 77 28 48 3b 77 20 74 59 <4c> 8b 6f 18 4c 8d 76 01 83 f8 08 4c 89 77 28 0f 4f c5 41 0f b6 74 RSP: 002b:00007fcce84bd5d0 EFLAGS: 00000287 ORIG_RAX: ffffffffffffff13 RAX: 000000000000000f RBX: 0000000000000000 RCX: 0000000000000000 RDX: 00007fcce84bd682 RSI: 000000000000538a RDI: 00007fcce84bd700 RBP: 0000000000000008 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000010 R11: 00007fcce84bd660 R12: 0000000000000000 R13: 00007fcce84bd700 R14: 0000000000000001 R15: 0000000000000000