INFO: task syz-executor.5:25600 blocked for more than 143 seconds. Not tainted 6.0.0-rc6-syzkaller-17742-gc194837ebb57 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.5 state:D stack: 0 pid:25600 ppid: 21249 flags:0x00000009 Call trace: __switch_to+0x180/0x298 arch/arm64/kernel/process.c:557 context_switch kernel/sched/core.c:5182 [inline] __schedule+0x414/0x5a0 kernel/sched/core.c:6494 schedule+0x64/0xa4 kernel/sched/core.c:6570 schedule_timeout+0x64/0x1b4 kernel/time/timer.c:1911 do_wait_for_common+0xf4/0x184 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x48/0x60 kernel/sched/completion.c:138 __flush_workqueue+0x2b0/0x6dc kernel/workqueue.c:2861 nbd_start_device_ioctl+0x188/0x25c drivers/block/nbd.c:1418 __nbd_ioctl+0x16c/0x334 drivers/block/nbd.c:1481 nbd_ioctl+0xec/0x13c drivers/block/nbd.c:1521 blkdev_ioctl+0x24c/0x6d8 block/ioctl.c:614 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/10: #0: ffff80000d433568 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x3c/0x450 kernel/rcu/tasks.h:507 1 lock held by rcu_tasks_trace/11: #0: ffff80000d433bb8 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x3c/0x450 kernel/rcu/tasks.h:507 1 lock held by khungtaskd/26: #0: ffff80000d433440 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x4/0x48 include/linux/rcupdate.h:279 2 locks held by kworker/u5:0/44: #0: ffff0000c59ad138 ((wq_completion)nbd5-recv){+.+.}-{0:0}, at: process_one_work+0x270/0x504 kernel/workqueue.c:2262 #1: ffff80000f653d80 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x29c/0x504 kernel/workqueue.c:2264 2 locks held by nbd5-recv/868: #0: ffff0000c59ad138 ((wq_completion)nbd5-recv){+.+.}-{0:0}, at: process_one_work+0x270/0x504 kernel/workqueue.c:2262 #1: ffff800013b5bd50 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x29c/0x504 kernel/workqueue.c:2264 2 locks held by getty/2714: #0: ffff0000c7cb2898 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x28/0x58 drivers/tty/tty_ldisc.c:244 #1: ffff80000f60e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x19c/0x89c drivers/tty/n_tty.c:2177 2 locks held by kworker/u5:3/3080: #0: ffff0000c59ad138 ((wq_completion)nbd5-recv){+.+.}-{0:0}, at: process_one_work+0x270/0x504 kernel/workqueue.c:2262 #1: ffff8000128bbd80 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x29c/0x504 kernel/workqueue.c:2264 3 locks held by kworker/0:7/3132: #0: ffff0000c0010738 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x270/0x504 kernel/workqueue.c:2262 #1: ffff800013673d80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x29c/0x504 kernel/workqueue.c:2264 #2: ffff80000d7eaa28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74 2 locks held by kworker/0:8/3133: #0: ffff0000c0010f38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x270/0x504 kernel/workqueue.c:2262 #1: ffff80001367bd80 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x29c/0x504 kernel/workqueue.c:2264 2 locks held by kworker/u4:12/11987: 2 locks held by kworker/u5:1/21251: #0: ffff0000c59ad138 ((wq_completion)nbd5-recv){+.+.}-{0:0}, at: process_one_work+0x270/0x504 kernel/workqueue.c:2262 #1: ffff800021a13d80 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x29c/0x504 kernel/workqueue.c:2264 5 locks held by syz-executor.2/1464: 2 locks held by syz-executor.4/1479: #0: ffff80000d7eaa28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74 #1: ffff80000d4349f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #1: ffff80000d4349f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x210/0x47c kernel/rcu/tree_exp.h:940 =============================================