INFO: task syz-executor:5836 blocked for more than 143 seconds.
Tainted: G U syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:23672 pid:5836 tgid:5836 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
nfsd_umount+0x48/0xe0 fs/nfsd/nfsctl.c:1386
deactivate_locked_super+0xbe/0x1a0 fs/super.c:474
deactivate_super fs/super.c:507 [inline]
deactivate_super+0xde/0x100 fs/super.c:503
cleanup_mnt+0x225/0x450 fs/namespace.c:1318
task_work_run+0x150/0x240 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x130 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x419/0x4b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f08de9901f7
RSP: 002b:00007fff061e5478 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f08dea11d7d RCX: 00007f08de9901f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff061e5530
RBP: 00007fff061e5530 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff061e65c0
R13: 00007f08dea11d7d R14: 00000000000364ab R15: 00007fff061e6600
Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
#0: ffffffff8e1cf538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
3 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/31:
#0: ffffffff8e1c3fa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e1c3fa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e1c3fa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:4/59:
#0: ffff88801bede948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1: ffffc9000210fd10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
#2: ffffffff8feca2b0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x8b0 net/core/net_namespace.c:669
2 locks held by syz-executor/5836:
#0: ffff88802854e0e0 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88802854e0e0 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88802854e0e0 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88802854e0e0 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e5e6388 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz-executor/5842:
#0: ffff8880280ec0e0 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880280ec0e0 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880280ec0e0 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff8880280ec0e0 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e5e6388 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
3 locks held by kworker/0:3/5880:
#0: ffff88801b059948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1: ffffc900043dfd10 ((work_completion)(&blkg->free_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
#2: ffffffff8e1cf538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
2 locks held by syz.1.179/7003:
#0: ffffffff8ff83f30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e5e6388 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629
2 locks held by syz-executor/7208:
#0: ffff88807b9a20e0 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88807b9a20e0 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88807b9a20e0 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88807b9a20e0 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e5e6388 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz.6.474/8869:
#0: ffffffff8ff83f30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e5e6388 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629
2 locks held by syz.6.474/8872:
#0: ffffffff8ff83f30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e5e6388 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629
2 locks held by syz-executor/9017:
#0: ffff8880121600e0 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880121600e0 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880121600e0 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff8880121600e0 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e5e6388 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by getty/9231:
#0: ffff8880343fd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900039232f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
1 lock held by syz.0.562/9647:
2 locks held by syz.7.574/9713:
#0: ffffffff8feca2b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x2d6/0x690 net/core/net_namespace.c:576
#1: ffffffff8fee06c8 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
#1: ffffffff8fee06c8 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7e9/0xab0 net/core/net_namespace.c:248
2 locks held by syz.9.575/9712:
#0: ffffffff8feca2b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x2d6/0x690 net/core/net_namespace.c:576
#1: ffffffff8fee06c8 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1b/0x230 drivers/net/wireguard/device.c:419
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U syzkaller #0 PREEMPT(full)
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
__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:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf3f/0x1170 kernel/hung_task.c:495
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5839 Comm: kworker/u9:4 Tainted: G U syzkaller #0 PREEMPT(full)
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: hci6 hci_cmd_timeout
RIP: 0010:format_decode+0x177/0xd40 lib/vsprintf.c:2672
Code: e2 07 42 0f b6 04 38 38 d0 7f 08 84 c0 0f 85 36 0a 00 00 44 0f b6 23 31 ff 44 89 e6 e8 12 63 75 f6 45 84 e4 0f 84 a8 05 00 00 24 68 75 f6 44 89 e6 bf 25 00 00 00 e8 f7 62 75 f6 41 80 fc 25
RSP: 0018:ffffc900041df618 EFLAGS: 00000006
RAX: 0000000000000000 RBX: ffffffff8cb8e206 RCX: ffffffff8b453d2e
RDX: ffff8880331c9e40 RSI: 0000000000000000 RDI: 0000000000000001
RBP: ffffc900041df6b8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000074 R11: 0000000000000000 R12: 0000000000000074
R13: ffffffff8cb8e200 R14: ffffc900041df738 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888124e8c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000f000 CR3: 000000000df82000 CR4: 00000000003526f0
Call Trace:
vsnprintf+0x156/0x1160 lib/vsprintf.c:2869
vscnprintf+0x40/0x90 lib/vsprintf.c:2991
printk_sprint+0x31/0x330 kernel/printk/printk.c:2189
vprintk_store+0x50e/0xbf0 kernel/printk/printk.c:2309
vprintk_emit+0x14d/0x680 kernel/printk/printk.c:2399
_printk+0xc7/0x100 kernel/printk/printk.c:2448
bt_err+0xe4/0x120 net/bluetooth/lib.c:296
hci_cmd_timeout+0xd1/0x260 net/bluetooth/hci_core.c:1469
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3263
process_scheduled_works kernel/workqueue.c:3346 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245