INFO: task syz.1.142:4791 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.142 state:D stack:0 pid:4791 ppid:4330 flags:0x00000001 Call trace: __switch_to+0x2f4/0x550 arch/arm64/kernel/process.c:555 context_switch kernel/sched/core.c:5246 [inline] __schedule+0xdb4/0x1a6c kernel/sched/core.c:6563 schedule+0xc4/0x170 kernel/sched/core.c:6639 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6698 __mutex_lock_common+0xb20/0x1f3c kernel/locking/mutex.c:679 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 nfsd_nrthreads+0x58/0xfc fs/nfsd/nfssvc.c:280 write_threads+0x1c0/0x310 fs/nfsd/nfsctl.c:428 nfsctl_transaction_write+0x114/0x164 fs/nfsd/nfsctl.c:114 vfs_write+0x2a8/0x7c8 fs/read_write.c:582 ksys_write+0x12c/0x228 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:646 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 INFO: task syz.4.243:5033 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.243 state:D stack:0 pid:5033 ppid:4341 flags:0x00000001 Call trace: __switch_to+0x2f4/0x550 arch/arm64/kernel/process.c:555 context_switch kernel/sched/core.c:5246 [inline] __schedule+0xdb4/0x1a6c kernel/sched/core.c:6563 schedule+0xc4/0x170 kernel/sched/core.c:6639 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6698 __mutex_lock_common+0xb20/0x1f3c kernel/locking/mutex.c:679 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 write_versions+0xa4/0xa34 fs/nfsd/nfsctl.c:681 nfsctl_transaction_write+0x114/0x164 fs/nfsd/nfsctl.c:114 vfs_write+0x2a8/0x7c8 fs/read_write.c:582 ksys_write+0x12c/0x228 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:646 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffff800015557db0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x40/0xc48 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffff8000155585d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x40/0xc48 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffff800015557440 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:349 1 lock held by syslogd/3926: #0: ffff00019f3c8398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:538 [inline] #0: ffff00019f3c8398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1362 [inline] #0: ffff00019f3c8398 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1652 [inline] #0: ffff00019f3c8398 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x2bc/0x1a6c kernel/sched/core.c:6479 2 locks held by getty/4084: #0: ffff0000d674d098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340 #1: ffff80002093e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x2e8/0xfa8 drivers/tty/n_tty.c:2198 3 locks held by syz.1.142/4790: #0: ffff0000d0b6dc68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x118/0x17c fs/file.c:1038 #1: ffff0000d293a460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x254/0x7c8 fs/read_write.c:580 #2: ffff8000157e3f68 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xbc/0x9f0 fs/nfsd/nfsctl.c:846 3 locks held by syz.1.142/4791: #0: ffff0000d1cdcae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x118/0x17c fs/file.c:1038 #1: ffff0000d293a460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x254/0x7c8 fs/read_write.c:580 #2: ffff8000157e3f68 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nrthreads+0x58/0xfc fs/nfsd/nfssvc.c:280 3 locks held by kworker/u4:8/4842: 3 locks held by syz.4.243/5033: #0: ffff0000d9d50d68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x118/0x17c fs/file.c:1038 #1: ffff0000d9dca460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x254/0x7c8 fs/read_write.c:580 #2: ffff8000157e3f68 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0xa4/0xa34 fs/nfsd/nfsctl.c:681 2 locks held by kworker/u4:14/5271: 2 locks held by syz.3.349/5369: #0: ffff0000d2e3c0e0 (&type->s_umount_key#50){+.+.}-{3:3}, at: deactivate_super+0xdc/0x104 fs/super.c:362 #1: ffff8000157e3f68 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x60/0x204 fs/nfsd/nfssvc.c:633 1 lock held by syz.0.1104/8404: #0: ffff00010629dc10 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #0: ffff00010629dc10 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline] #0: ffff00010629dc10 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: sock_close+0x74/0x1ec net/socket.c:1400 1 lock held by rm/8422: =============================================