INFO: task syz.1.343:5511 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.343 state:D stack:0 pid:5511 ppid:4329 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 __fdget_pos+0x118/0x17c fs/file.c:1038 fdget_pos include/linux/file.h:75 [inline] ksys_write+0x8c/0x228 fs/read_write.c:628 __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 dhcpcd/3994: #0: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x64c/0xcc4 net/core/rtnetlink.c:6163 2 locks held by getty/4085: #0: ffff0000d6c07098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340 #1: ffff80001fa032f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x2e8/0xfa8 drivers/tty/n_tty.c:2198 3 locks held by kworker/u5:2/4333: #0: ffff0000db310938 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1 #1: ffff800020ec7c40 ((work_completion)(&hdev->error_reset)){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267 #2: ffff0001076f54b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_open net/bluetooth/hci_core.c:455 [inline] #2: ffff0001076f54b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_error_reset+0x130/0x33c net/bluetooth/hci_core.c:1040 3 locks held by kworker/1:4/4375: #0: ffff0000d6517938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1 #1: ffff8000213d7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267 #2: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74 3 locks held by kworker/u4:15/4993: #0: ffff0000c0029138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1 #1: ffff800020ad7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267 #2: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74 3 locks held by syz.1.343/5508: #0: ffff0000e0020fe8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x118/0x17c fs/file.c:1038 #1: ffff0000cd2ae460 (sb_writers#22){.+.+}-{0:0}, at: vfs_write+0x254/0x7c8 fs/read_write.c:580 #2: ffff8000157e3f68 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x74/0x948 fs/nfsd/nfssvc.c:783 1 lock held by syz.1.343/5511: #0: ffff0000e0020fe8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x118/0x17c fs/file.c:1038 3 locks held by kworker/1:10/5783: 2 locks held by kworker/1:13/6849: #0: ffff0000c0021938 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1 #1: ffff8000211b7c40 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267 2 locks held by syz.8.1109/9203: #0: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x64c/0xcc4 net/core/rtnetlink.c:6163 #1: ffff80001555d0f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #1: ffff80001555d0f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3f8/0x780 kernel/rcu/tree_exp.h:962 3 locks held by syz.9.1111/9214: #0: ffff800017a615b0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x28/0x50 net/netlink/genetlink.c:860 #1: ffff0001120ca698 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: __netlink_dump_start+0x104/0x694 net/netlink/af_netlink.c:2310 #2: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74 1 lock held by syz.1.1117/9237: #0: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74 =============================================