INFO: task syz-executor:5631 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:23344 pid:5631 tgid:5631 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: 0033:0x7f3186f9f097
RSP: 002b:00007ffe58625448 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f31870332ca RCX: 00007f3186f9f097
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe58625500
RBP: 00007ffe58625500 R08: 00007ffe58626500 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe58626590
R13: 00007f31870332ca R14: 0000000000057250 R15: 00007ffe586265d0
INFO: task syz.0.766:9665 blocked for more than 144 seconds.
Tainted: G U L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.766 state:D stack:27560 pid:9665 tgid:9663 ppid:5632 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_nl_threads_set_doit+0x8c8/0x1100 fs/nfsd/nfsctl.c:1660
genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec net/socket.c:775 [inline]
__sock_sendmsg net/socket.c:790 [inline]
____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2684
___sys_sendmsg+0x190/0x1e0 net/socket.c:2738
__sys_sendmsg+0x160/0x210 net/socket.c:2770
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb3cad9de59
RSP: 002b:00007fb3cbcf7028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fb3cb025fa0 RCX: 00007fb3cad9de59
RDX: 0000000000040010 RSI: 0000200000000000 RDI: 0000000000000007
RBP: 00007fb3cae33e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb3cb026038 R14: 00007fb3cb025fa0 R15: 00007ffd06d38968
Showing all locks held in the system:
2 locks held by kworker/0:0/9:
#0: ffff8880b843b660 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x140 kernel/sched/core.c:667
#1: ffff88802371a008 (&____s->seqcount#17){.-.-}-{0:0}, at: trace_find_filtered_pid kernel/trace/trace_pid.c:15 [inline]
#1: ffff88802371a008 (&____s->seqcount#17){.-.-}-{0:0}, at: trace_ignore_this_task+0x56/0x100 kernel/trace/trace_pid.c:42
1 lock held by khungtaskd/30:
#0: ffffffff8ebe5f00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8ebe5f00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8ebe5f00 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by syz-executor/5629:
#0: ffff888034d4c0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888034d4c0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888034d4c0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff888034d4c0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f260 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/5631:
#0: ffff8880364ca0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880364ca0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff8880364ca0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff8880364ca0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f260 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz.2.732/9509:
#0: ffffffff90b4c928 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f06f260 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964
2 locks held by syz.0.766/9665:
#0: ffffffff90b4c928 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f06f260 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x8c8/0x1100 fs/nfsd/nfsctl.c:1660
2 locks held by syz-executor/9749:
#0: ffff888059f9a0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888059f9a0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888059f9a0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff888059f9a0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f260 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
3 locks held by kworker/0:6/9824:
#0: ffff88801bc07140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc90004c4fd08 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffffffff8ebf1878 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3857
2 locks held by syz-executor/9868:
#0: ffff88806a5ac0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88806a5ac0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88806a5ac0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88806a5ac0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f260 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/9921:
#0: ffff88807f9440d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88807f9440d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88807f9440d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88807f9440d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f260 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by getty/10189:
#0: ffff888029b5c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000429b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
3 locks held by kworker/u8:22/10583:
#0: ffff88801caf6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc90003587d08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffffffff8ebf1878 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3857
2 locks held by syz-executor/10611:
#0: ffff88802ce1a0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88802ce1a0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88802ce1a0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88802ce1a0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f260 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
5 locks held by syz-executor/10914:
#0: ffff88807bb2cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:497
#1: ffff88807bb2c0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x37e/0x13c0 net/bluetooth/hci_sync.c:5393
#2: ffffffff90d28c20 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2148 [inline]
#2: ffffffff90d28c20 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x280 net/bluetooth/hci_conn.c:2733
#3: ffff888077edbaf8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x95/0x710 net/bluetooth/l2cap_core.c:1778
#4: ffffffff8ebf19a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
2 locks held by syz-executor/11089:
#0: ffff888032de40d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888032de40d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888032de40d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff888032de40d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f260 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz.2.1082/11581:
#0: ffff88805a984ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:497
#1: ffff88805a9840b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x37e/0x13c0 net/bluetooth/hci_sync.c:5393
2 locks held by syz.0.1083/11577:
#0: ffffffff90a85268 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff8ebf1878 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3857
=============================================
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 05/09/2026
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