INFO: task syz-executor.0:17227 blocked for more than 143 seconds. Not tainted 6.0.0-rc4-syzkaller-17255-ga6b443748715 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack: 0 pid:17227 ppid: 3064 flags:0x00000009 Call trace: __switch_to+0x180/0x28c 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+0x250/0x764 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:624 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:642 el0t_64_sync+0x18c/0x190 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/10: #0: ffff80000d4634e8 (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: ffff80000d463b38 (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: ffff80000d4633c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x4/0x48 include/linux/rcupdate.h:279 2 locks held by kworker/1:2/916: #0: ffff0000c0010f38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x270/0x504 kernel/workqueue.c:2262 #1: ffff800013c73d80 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x29c/0x504 kernel/workqueue.c:2264 2 locks held by udevd/2560: 2 locks held by getty/2717: #0: ffff0000c71fb898 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x28/0x58 drivers/tty/tty_ldisc.c:244 #1: ffff80000f63e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x19c/0x89c drivers/tty/n_tty.c:2177 2 locks held by kworker/u5:3/3079: #0: ffff0000c5e0d538 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x270/0x504 kernel/workqueue.c:2262 #1: ffff800012a9bd80 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x29c/0x504 kernel/workqueue.c:2264 3 locks held by kworker/u4:12/28714: 2 locks held by kworker/u5:0/17356: #0: ffff0000c0f52538 ((wq_completion)nbd3-recv){+.+.}-{0:0}, at: process_one_work+0x270/0x504 kernel/workqueue.c:2262 #1: ffff800020d7bd80 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x29c/0x504 kernel/workqueue.c:2264 1 lock held by syz-executor.5/24125: #0: ffff0000c0f56598 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x70/0x13c drivers/block/nbd.c:1514 1 lock held by syz-executor.5/24136: #0: ffff0000c0f56598 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x70/0x13c drivers/block/nbd.c:1514 1 lock held by syz-executor.5/24141: #0: ffff0000c0f56598 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x70/0x13c drivers/block/nbd.c:1514 2 locks held by syz-executor.2/24126: #0: ffff80000d81a928 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffff80000d81a928 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x458/0x82c net/core/rtnetlink.c:6087 #1: ffff80000d464978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #1: ffff80000d464978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x210/0x47c kernel/rcu/tree_exp.h:940 1 lock held by syz-executor.2/24139: #0: ffff80000d81a928 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffff80000d81a928 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x458/0x82c net/core/rtnetlink.c:6087 1 lock held by syz-executor.2/24142: #0: ffff80000d81a928 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffff80000d81a928 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x458/0x82c net/core/rtnetlink.c:6087 2 locks held by syz-executor.4/24145: #0: ffff0000c58b7cc8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x78/0x284 block/bdev.c:910 #1: ffff0000c0f53598 (&nbd->config_lock){+.+.}-{3:3}, at: refcount_dec_and_mutex_lock+0xd4/0x1f0 lib/refcount.c:118 2 locks held by syz-executor.0/24152: 2 locks held by syz-executor.3/24153: =============================================