INFO: task syz.0.906:11542 blocked for more than 145 seconds. Not tainted 6.11.0-next-20240926-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.906 state:D stack:25792 pid:11542 tgid:11533 ppid:11053 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6824 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752 nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:625 nfsd_umount+0x43/0xd0 fs/nfsd/nfsctl.c:1428 deactivate_locked_super+0xc4/0x130 fs/super.c:473 put_fs_context+0x94/0x780 fs/fs_context.c:516 fscontext_release+0x62/0x80 fs/fsopen.c:73 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd4d2b7df39 RSP: 002b:00007fd4d3a1c038 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fd4d2d36130 RCX: 00007fd4d2b7df39 RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000000 RBP: 00007fd4d2bf0216 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fd4d2d36130 R15: 00007ffee5975ca8 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e93d4b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #0: ffffffff8e93d4b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 3 locks held by kworker/u8:0/11: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000107d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 1 lock held by khungtaskd/30: #0: ffffffff8e937f20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937f20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937f20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 2 locks held by getty/4985: #0: ffff88802e8030a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002efe2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by kworker/u8:11/6682: #0: ffff88814ba88948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88814ba88948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90003837d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90003837d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196 3 locks held by kworker/u8:12/6692: #0: ffff8880b863ea98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:601 #1: ffffc9000326fd00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000326fd00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8e937f20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #2: ffffffff8e937f20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8e937f20 (rcu_read_lock){....}-{1:2}, at: batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] #2: ffffffff8e937f20 (rcu_read_lock){....}-{1:2}, at: batadv_nc_worker+0xcb/0x610 net/batman-adv/network-coding.c:719 5 locks held by kworker/u8:16/6708: #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900039b7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900039b7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcc8690 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580 #3: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:414 #4: ffff88806285d428 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_netns_pre_exit+0xba/0x1e0 drivers/net/wireguard/device.c:419 2 locks held by syz.4.803/10625: #0: ffffffff8fd3aef0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ec1c2e8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_listener_set_doit+0x12d/0x1a90 fs/nfsd/nfsctl.c:1964 1 lock held by syz-executor/10891: #0: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 1 lock held by syz-executor/11126: #0: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 2 locks held by syz.0.906/11542: #0: ffff8880306180e0 (&type->s_umount_key#118){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880306180e0 (&type->s_umount_key#118){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880306180e0 (&type->s_umount_key#118){++++}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:505 #1: ffffffff8ec1c2e8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:625 1 lock held by syz.0.995/11946: #0: ffff8880306180e0 (&type->s_umount_key#118){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880306180e0 (&type->s_umount_key#118){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 3 locks held by syz-executor/12043: #0: ffff888067ce8d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff888067ce8d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2698 #1: ffff888067ce8078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x572/0x11a0 net/bluetooth/hci_sync.c:5183 #2: ffffffff8e93d4b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #2: ffffffff8e93d4b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 1 lock held by syz-executor/12381: #0: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 1 lock held by syz-executor/12388: #0: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 1 lock held by syz-executor/12390: #0: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 2 locks held by syz-executor/12391: #0: ffffffff8fcc8690 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490 #1: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: register_nexthop_notifier+0x84/0x290 net/ipv4/nexthop.c:3885 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-next-20240926-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111