INFO: task syz-executor384:5994 blocked for more than 143 seconds. Not tainted 6.4.0-rc7-syzkaller-ge40939bbfc68 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor384 state:D stack:0 pid:5994 ppid:5993 flags:0x00000009 Call trace: __switch_to+0x320/0x754 arch/arm64/kernel/process.c:556 context_switch kernel/sched/core.c:5343 [inline] __schedule+0x1368/0x23b8 kernel/sched/core.c:6669 schedule+0xc4/0x170 kernel/sched/core.c:6745 schedule_timeout+0xb8/0x348 kernel/time/timer.c:2143 do_wait_for_common+0x30c/0x468 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+0x580/0x11c4 kernel/workqueue.c:2977 nbd_start_device_ioctl drivers/block/nbd.c:1426 [inline] __nbd_ioctl drivers/block/nbd.c:1488 [inline] nbd_ioctl+0x8dc/0xc40 drivers/block/nbd.c:1528 blkdev_ioctl+0x408/0xb40 block/ioctl.c:615 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+0x14c/0x1c8 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x244 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:191 el0_svc+0x4c/0x160 arch/arm64/kernel/entry-common.c:647 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffff80008e0916d0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:518 1 lock held by rcu_tasks_trace/14: #0: ffff80008e091a90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:518 1 lock held by khungtaskd/29: #0: ffff80008e091500 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:326 2 locks held by kworker/u5:1/5548: #0: ffff0000ccce0938 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x664/0x12d4 kernel/workqueue.c:2378 #1: ffff800098687c20 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x12d4 kernel/workqueue.c:2380 2 locks held by getty/5729: #0: ffff0000cf3fb098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340 #1: ffff800092e002f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1210 drivers/tty/n_tty.c:2176 =============================================