INFO: task syz-executor:17210 blocked for more than 143 seconds.
Tainted: G U L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:23400 pid:17210 tgid:17210 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7326
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0xccc/0x1bd0 kernel/locking/mutex.c:821
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
nfsd_umount+0x3b/0x60 fs/nfsd/nfsctl.c:1365
deactivate_locked_super+0xc1/0x1b0 fs/super.c:477
deactivate_super fs/super.c:510 [inline]
deactivate_super+0xe7/0x110 fs/super.c:506
cleanup_mnt+0x21f/0x450 fs/namespace.c:1317
task_work_run+0x150/0x240 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
exit_to_user_mode_loop+0x1d8/0x6f0 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x652/0x840 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe008b9f097
RSP: 002b:00007ffeff933a88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fe008c332ca RCX: 00007fe008b9f097
RDX: 0000000000000004 RSI: 0000000000000009 RDI: 00007ffeff934bd0
RBP: 00007ffeff934bbc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffeff934bd0
R13: 00007fe008c332ca R14: 00000000000fa2c5 R15: 00007ffeff934c10
Showing all locks held in the system:
3 locks held by kworker/0:1/10:
#0: ffff8880b843b660 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x140 kernel/sched/core.c:667
#1: ffff8880b8424568 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:218 [inline]
#1: ffff8880b8424568 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2e8e/0x6730 kernel/sched/core.c:7228
#2: ffffffff8ebe5f80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#2: ffffffff8ebe5f80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#2: ffffffff8ebe5f80 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
#2: ffffffff8ebe5f80 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495
1 lock held by khungtaskd/30:
#0: ffffffff8ebe5f80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8ebe5f80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8ebe5f80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by syz-executor/5642:
#0: ffff888080cf80d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888080cf80d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888080cf80d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff888080cf80d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f2a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by getty/12601:
#0: ffff8880378070a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc90003d0b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/14006:
#0: ffff888082ada0d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888082ada0d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888082ada0d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff888082ada0d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f2a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
4 locks held by kworker/u10:8/15562:
#0: ffff88801bc4c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc9000432fd08 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffffffff90a9ed40 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:313
#3: ffffffff8ebf1a28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by dhcpcd/16729:
#0: ffff88805c911380 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#0: ffff88805c911380 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x86/0x260 net/socket.c:709
2 locks held by syz-executor/17210:
#0: ffff88802d0d60d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88802d0d60d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88802d0d60d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88802d0d60d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f2a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz.4.2136/17705:
#0: ffffffff90b4d948 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f06f2a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964
2 locks held by syz-executor/17891:
#0: ffff888029d140d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888029d140d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888029d140d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff888029d140d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f2a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz.8.2268/18479:
#0: ffffffff90b4d948 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f06f2a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964
2 locks held by syz.8.2268/18481:
#0: ffffffff90b4d948 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f06f2a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964
2 locks held by syz-executor/18625:
#0: ffff8880134940d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880134940d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff8880134940d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff8880134940d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f2a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/19175:
#0: ffff888033cc80d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888033cc80d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888033cc80d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff888033cc80d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f2a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/19250:
#0: ffff8880281f20d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880281f20d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff8880281f20d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff8880281f20d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f2a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
1 lock held by syz.9.2419/19823:
#0: ffffffff8ebf1a28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
1 lock held by syz-executor/19918:
#0: ffff88808987cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:497
2 locks held by dhcpcd-run-hook/19989:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G U L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x21c/0x2a0 lib/nmi_backtrace.c:65
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245