INFO: task kworker/u4:2:23561 blocked for more than 143 seconds. Not tainted 5.16.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:2 state:D stack:24464 pid:23561 ppid: 2 flags:0x00004000 Workqueue: nbd-del nbd_dev_remove_work Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178 del_gendisk+0x598/0x860 block/genhd.c:623 nbd_dev_remove+0x3c/0xf0 drivers/block/nbd.c:252 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Showing all locks held in the system: 2 locks held by kworker/u4:1/10: 1 lock held by khungtaskd/27: #0: ffffffff8bb83b60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6211: #0: ffff8880783e3270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by rs:main Q:Reg/6214: #0: ffff88801d856d70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 #1: ffff88807ec78460 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x12d/0x250 fs/read_write.c:643 2 locks held by agetty/6228: #0: ffff888018800098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252 #1: ffffc900030432e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2113 2 locks held by kworker/u4:2/23561: #0: ffff88801add5938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801add5938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88801add5938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff88801add5938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff88801add5938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff88801add5938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc900049f7db0 ((work_completion)(&nbd->remove_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 5 locks held by kworker/1:5/25764: #0: ffff888142596938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888142596938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888142596938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888142596938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff888142596938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff888142596938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc9000507fdb0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 #2: ffff88801dd70220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #2: ffff88801dd70220 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4330 drivers/usb/core/hub.c:5662 #3: ffff88801dd735c0 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3086 [inline] #3: ffff88801dd735c0 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5279 [inline] #3: ffff88801dd735c0 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5488 [inline] #3: ffff88801dd735c0 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5634 [inline] #3: ffff88801dd735c0 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x2178/0x4330 drivers/usb/core/hub.c:5716 #4: ffff88801da15f68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_init+0x1b5/0x2f10 drivers/usb/core/hub.c:4703 2 locks held by syz-executor.0/15264: #0: ffff88801e85c130 (&clk->rwsem){.+.+}-{3:3}, at: get_posix_clock kernel/time/posix-clock.c:24 [inline] #0: ffff88801e85c130 (&clk->rwsem){.+.+}-{3:3}, at: posix_clock_read+0x54/0x190 kernel/time/posix-clock.c:42 #1: ffff88801e85d760 (&ptp->tsevq_mux){+.+.}-{3:3}, at: ptp_read+0xd3/0x7e0 drivers/ptp/ptp_chardev.c:461 1 lock held by syz-executor.3/19955: #0: ffffffff8bb8cee8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #0: ffffffff8bb8cee8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4fa/0x620 kernel/rcu/tree_exp.h:836 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xc1d/0xf50 kernel/hung_task.c:295 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 23558 Comm: kworker/u4:0 Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bond4 bond_mii_monitor RIP: 0010:enqueue_timer+0x2/0x5c0 kernel/time/timer.c:580 Code: bc 01 00 00 00 e8 ae fd ff ff 48 89 ef 48 c7 c6 60 f6 ad 89 e8 5f 5b 78 02 e8 ea 19 11 00 44 89 e0 5b 5d 41 5c c3 66 90 41 57 <41> 89 d7 41 56 4d 89 fe 41 55 49 89 cd 41 54 55 48 89 fd 53 4e 8d RSP: 0018:ffffc9000494fa40 EFLAGS: 00000093 RAX: 0000000000000004 RBX: ffff8880b9c28280 RCX: 000000010001c184 RDX: 0000000000000004 RSI: ffff88803bd9cf28 RDI: ffff8880b9c28280 RBP: ffff88803bd9cf28 R08: 000000000000003e R09: ffffffff9074761b R10: ffffffff8165fd77 R11: 0000000000000000 R12: 000000010001c17a R13: ffff8880b9c28280 R14: 0000000000000000 R15: 00000000ffffffff FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd5862d0718 CR3: 000000000b88e000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: internal_add_timer kernel/time/timer.c:611 [inline] __mod_timer+0x825/0xe30 kernel/time/timer.c:1062 __queue_delayed_work+0x1a7/0x270 kernel/workqueue.c:1678 queue_delayed_work_on+0x105/0x120 kernel/workqueue.c:1703 queue_delayed_work include/linux/workqueue.h:517 [inline] bond_mii_monitor+0x95b/0x1af0 drivers/net/bonding/bond_main.c:2759 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: bc 01 00 00 00 mov $0x1,%esp 5: e8 ae fd ff ff callq 0xfffffdb8 a: 48 89 ef mov %rbp,%rdi d: 48 c7 c6 60 f6 ad 89 mov $0xffffffff89adf660,%rsi 14: e8 5f 5b 78 02 callq 0x2785b78 19: e8 ea 19 11 00 callq 0x111a08 1e: 44 89 e0 mov %r12d,%eax 21: 5b pop %rbx 22: 5d pop %rbp 23: 41 5c pop %r12 25: c3 retq 26: 66 90 xchg %ax,%ax 28: 41 57 push %r15 * 2a: 41 89 d7 mov %edx,%r15d <-- trapping instruction 2d: 41 56 push %r14 2f: 4d 89 fe mov %r15,%r14 32: 41 55 push %r13 34: 49 89 cd mov %rcx,%r13 37: 41 54 push %r12 39: 55 push %rbp 3a: 48 89 fd mov %rdi,%rbp 3d: 53 push %rbx 3e: 4e rex.WRX 3f: 8d .byte 0x8d