INFO: task syz.5.841:10179 blocked for more than 143 seconds.
      Not tainted 6.13.0-rc5-syzkaller-00161-g63676eefb7a0 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.841       state:D stack:27248 pid:10179 tgid:10176 ppid:10018  flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6848
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905
 __mutex_lock_common kernel/locking/mutex.c:665 [inline]
 __mutex_lock+0x62b/0xa60 kernel/locking/mutex.c:735
 nfsd_nl_version_set_doit+0xc5/0x7a0 fs/nfsd/nfsctl.c:1813
 genl_family_rcv_msg_doit+0x202/0x2f0 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x565/0x800 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2542
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
 netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1347
 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1891
 sock_sendmsg_nosec net/socket.c:711 [inline]
 __sock_sendmsg net/socket.c:726 [inline]
 ____sys_sendmsg+0x9ae/0xb40 net/socket.c:2583
 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2637
 __sys_sendmsg+0x16e/0x220 net/socket.c:2669
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3448985d29
RSP: 002b:00007f3449842038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3448b76080 RCX: 00007f3448985d29
RDX: 0000000000004010 RSI: 00000000200004c0 RDI: 0000000000000004
RBP: 00007f3448a01b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f3448b76080 R15: 00007fffcd845148
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:0/11:
 #0: ffff8880309b0148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12cd/0x1b30 kernel/workqueue.c:3204
 #1: ffffc90000107d80 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3205
 #2: ffffffff8fabfdc8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0xcf/0x14d0 net/ipv6/addrconf.c:4215
1 lock held by khungtaskd/30:
 #0: ffffffff8ddbad40 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8ddbad40 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ddbad40 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6744
2 locks held by kworker/0:5/5877:
 #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12cd/0x1b30 kernel/workqueue.c:3204
 #1: ffffc9000423fd80 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3205
2 locks held by getty/6870:
 #0: ffff8880315850a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900046332f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211
4 locks held by kworker/u8:39/9835:
 #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12cd/0x1b30 kernel/workqueue.c:3204
 #1: ffffc9000b5dfd80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3205
 #2: ffffffff8faa9dd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xbb/0xbd0 net/core/net_namespace.c:602
 #3: ffffffff8fabfdc8 (rtnl_mutex){+.+.}-{4:4}, at: cleanup_net+0x503/0xbd0 net/core/net_namespace.c:638
2 locks held by syz.0.823/10090:
 #0: ffffffff8fb5e650 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffffffff8e1bb108 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1671
2 locks held by syz.5.841/10179:
 #0: ffffffff8fb5e650 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffffffff8e1bb108 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_set_doit+0xc5/0x7a0 fs/nfsd/nfsctl.c:1813
3 locks held by syz-executor/10188:
 #0: ffff888040378d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:480
 #1: ffff888040378078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x34c/0x1250 net/bluetooth/hci_sync.c:5200
 #2: ffffffff8ddc6678 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:329
2 locks held by syz-executor/10271:
 #0: ffff88807a3da0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88807a3da0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88807a3da0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:505
 #1: ffffffff8e1bb108 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:625
2 locks held by syz.6.925/10634:
 #0: ffffffff8fb5e650 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffffffff8e1bb108 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xe3/0x1b40 fs/nfsd/nfsctl.c:1964
3 locks held by syz.9.1112/11654:
 #0: ffffffff8fb5e650 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffff88802744d6c8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0x154/0x980 net/netlink/af_netlink.c:2396
 #2: ffffffff8e1bb108 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xb1/0x1160 fs/nfsd/nfsctl.c:1558
2 locks held by syz.3.1161/12338:
 #0: ffffffff8faa9dd0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x292/0x6c0 net/core/net_namespace.c:512
 #1: ffffffff8ddc6678 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:329
2 locks held by syz.1.1163/12351:
 #0: ffff8880356d0d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:480
 #1: ffff8880356d0078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x34c/0x1250 net/bluetooth/hci_sync.c:5200

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc5-syzkaller-00161-g63676eefb7a0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:234 [inline]
 watchdog+0xf14/0x1240 kernel/hung_task.c:397
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>