INFO: task syz.2.430:5616 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.430 state:D stack:0 pid:5616 ppid:4340 flags:0x00000001 dump_backtrace(regs = 0000000000000000 tsk = 000000000555818f) 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 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffff800015597db0 (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: ffff8000155985d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x40/0xc48 kernel/rcu/tasks.h:517 2 locks held by ksoftirqd/0/15: 1 lock held by khungtaskd/28: #0: ffff800015597440 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:349 2 locks held by kworker/u4:3/241: 1 lock held by klogd/3928: 2 locks held by getty/4081: #0: ffff0000d6b3f098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340 #1: ffff80001ea332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x2e8/0xfa8 drivers/tty/n_tty.c:2198 2 locks held by kworker/u4:10/4623: #0: ffff0000c0029138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1 #1: ffff800020cc7c40 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267 3 locks held by kworker/u4:12/4625: #0: ffff00019f360398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:538 [inline] #0: ffff00019f360398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1362 [inline] #0: ffff00019f360398 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1652 [inline] #0: ffff00019f360398 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x2bc/0x1a6c kernel/sched/core.c:6479 #1: ffff00019f34cbc8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x35c/0x5b8 kernel/sched/psi.c:999 #2: ffff0000ce66b0d8 (&lo->lo_work_lock){..-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] #2: ffff0000ce66b0d8 (&lo->lo_work_lock){..-.}-{2:2}, at: loop_process_work+0x9dc/0x200c drivers/block/loop.c:1945 3 locks held by kworker/u4:13/4626: #0: ffff0000c0029138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1 #1: ffff800021407c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267 #2: ffff800017a3ebc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74 3 locks held by syz.2.430/5613: #0: ffff0000c3d92ae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x118/0x17c fs/file.c:1038 #1: ffff0001204f8460 (sb_writers#22){.+.+}-{0:0}, at: vfs_write+0x254/0x7c8 fs/read_write.c:580 #2: ffff8000158242c8 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xbc/0x9f0 fs/nfsd/nfsctl.c:846 3 locks held by syz.2.430/5616: #0: ffff0000d9d7e868 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x118/0x17c fs/file.c:1038 #1: ffff0001204f8460 (sb_writers#22){.+.+}-{0:0}, at: vfs_write+0x254/0x7c8 fs/read_write.c:580 #2: ffff8000158242c8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nrthreads+0x58/0xfc fs/nfsd/nfssvc.c:280 4 locks held by kworker/u4:18/7371: #0: ffff0000c0845138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1 #1: ffff800021e17c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267 #2: ffff800017a32350 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x144/0xa90 net/core/net_namespace.c:594 #3: ffff0000f37253e8 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_destruct+0x114/0x2d4 drivers/net/wireguard/device.c:249 2 locks held by kworker/0:10/7544: #0: ffff0000c0020938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1 #1: ffff800021b57c40 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267 2 locks held by kworker/0:15/7549: #0: ffff0000c0021938 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1 #1: ffff800021e47c40 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267 3 locks held by syz.8.904/7908: #0: ffff000132cfe868 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x118/0x17c fs/file.c:1038 #1: ffff000142a3a460 (sb_writers#22){.+.+}-{0:0}, at: vfs_write+0x254/0x7c8 fs/read_write.c:580 #2: ffff8000158242c8 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0xa4/0xa34 fs/nfsd/nfsctl.c:681 1 lock held by syz-executor/8302: 3 locks held by udevd/8326: 1 lock held by syz.4.987/8362: #0: ffff00013f4d80e0 (&type->s_umount_key#71/1){+.+.}-{3:3}, at: alloc_super+0x1a0/0x840 fs/super.c:228 2 locks held by syz.3.988/8367: #0: ffff800017a9b610 (cb_lock){++++}-{3:3}, at: genl_rcv+0x28/0x50 net/netlink/genetlink.c:860 #1: ffff800017a3ebc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74 1 lock held by syz.3.988/8369: #0: ffff800017a3ebc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74 1 lock held by syz.3.988/8372: #0: ffff800017a3ebc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74 2 locks held by dhcpcd/8380: #0: ffff0001346d6130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline] #0: ffff0001346d6130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x48/0xaf4 net/packet/af_packet.c:3282 #1: ffff80001559d0f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #1: ffff80001559d0f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3f8/0x780 kernel/rcu/tree_exp.h:962 1 lock held by udevadm/8395: 3 locks held by dhcpcd/8396: #0: ffff0000d3690130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline] #0: ffff0000d3690130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x48/0xaf4 net/packet/af_packet.c:3282 #1: ffff00019f381398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:538 [inline] #1: ffff00019f381398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1362 [inline] #1: ffff00019f381398 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1652 [inline] #1: ffff00019f381398 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x2bc/0x1a6c kernel/sched/core.c:6479 #2: ffff00019f36dbc8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x35c/0x5b8 kernel/sched/psi.c:999 =============================================