INFO: task syz-executor:5629 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22584 pid:5629 tgid:5629 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: 0033:0x7f97a239e097
RSP: 002b:00007fff6bacfc88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f97a24322ca RCX: 00007f97a239e097
RDX: 0000000000000004 RSI: 0000000000000009 RDI: 00007fff6bad0dd0
RBP: 00007fff6bad0dbc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff6bad0dd0
R13: 00007f97a24322ca R14: 000000000008d269 R15: 00007fff6bad0e10
INFO: task syz-executor:14526 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:24024 pid:14526 tgid:14526 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: 0033:0x7f310bb9e097
RSP: 002b:00007fff98691f28 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f310bc322ca RCX: 00007f310bb9e097
RDX: 0000000000000004 RSI: 0000000000000009 RDI: 00007fff98693070
RBP: 00007fff9869305c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff98693070
R13: 00007f310bc322ca R14: 000000000008e56f R15: 00007fff986930b0
INFO: task syz.0.2052:14966 blocked for more than 145 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2052 state:D stack:27784 pid:14966 tgid:14965 ppid:10541 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: 0033:0x7f0d1e59ce59
RSP: 002b:00007f0d1f396028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: fffffffffffffffe RBX: 00007f0d1e815fa0 RCX: 00007f0d1e59ce59
RDX: 0000200000000140 RSI: 00002000000000c0 RDI: 0000000000000000
RBP: 00007f0d1e632e6f R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000000f R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0d1e816038 R14: 00007f0d1e815fa0 R15: 00007fff0b674ac8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e7e5ec0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e7e5ec0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8e7e5ec0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by getty/5381:
#0: ffff8880362980a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/5629:
#0: ffff88802a6860d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88802a6860d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88802a6860d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88802a6860d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz.2.1868/14157:
#0: ffffffff906efda8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964
2 locks held by syz-executor/14526:
#0: ffff88804ef3a0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88804ef3a0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88804ef3a0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88804ef3a0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz.0.2052/14966:
#0: ffff888056d2c0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888056d2c0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888056d2c0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff888056d2c0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/15115:
#0: ffff88807a6f80d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88807a6f80d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88807a6f80d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88807a6f80d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/15214:
#0: ffff888076b0e0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888076b0e0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888076b0e0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff888076b0e0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
4 locks held by kworker/u8:13/15347:
#0: ffff88801c6c6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc90003d97d08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffffffff906288e8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:673
#3: ffffffff90641500 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x4d/0x360 net/mac80211/main.c:1710
2 locks held by syz-executor/15621:
#0: ffff88807963c0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88807963c0d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88807963c0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88807963c0d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/15835:
#0: ffff88808c2a20d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88808c2a20d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88808c2a20d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88808c2a20d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/15926:
#0: ffff88802cf140d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88802cf140d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88802cf140d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88802cf140d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz.3.2353/16783:
#0: ffffffff906efda8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_svc_export_set_reqs_doit+0x8a/0x2f0 fs/nfsd/export.c:1057
1 lock held by syz.4.2415/17089:
#0: ffffffff90641500 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:641 [inline]
#0: ffffffff90641500 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3506
2 locks held by syz-executor/17170:
#0: ffff888086994ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:497
#1: ffffffff8e7f1968 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
3 locks held by syz.7.2438/17213:
#0: ffffffff906288e8 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff90641500 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
#1: ffffffff90641500 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248
#2: ffffffff8e7f1968 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
2 locks held by syz.0.2440/17228:
#0: ffffffff906288e8 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff90641500 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
#1: ffffffff90641500 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [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