INFO: task syz-executor:5633 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:23688 pid:5633 tgid:5633 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:820
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
nfsd_umount+0x3b/0x60 fs/nfsd/nfsctl.c:1364
deactivate_locked_super+0xc1/0x1b0 fs/super.c:476
deactivate_super fs/super.c:509 [inline]
deactivate_super+0xe7/0x110 fs/super.c:505
cleanup_mnt+0x21f/0x450 fs/namespace.c:1312
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:67 [inline]
exit_to_user_mode_loop+0x157/0x670 kernel/entry/common.c:98
__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: 0033:0x7f3a7239e097
RSP: 002b:00007ffcb05d6ec8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f3a724321ca RCX: 00007f3a7239e097
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcb05d6f80
RBP: 00007ffcb05d6f80 R08: 00007ffcb05d7f80 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcb05d8010
R13: 00007f3a724321ca R14: 0000000000038581 R15: 00007ffcb05d8050
INFO: task syz.2.539:8428 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.2.539 state:D stack:27744 pid:8428 tgid:8426 ppid:5636 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:820
nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1948
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:2555
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1899
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x9e1/0xb70 net/socket.c:2698
___sys_sendmsg+0x190/0x1e0 net/socket.c:2752
__sys_sendmsg+0x170/0x220 net/socket.c:2784
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: 0033:0x7f95ad59ce59
RSP: 002b:00007f95ae496028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f95ad816090 RCX: 00007f95ad59ce59
RDX: 0000000020000000 RSI: 0000200000000140 RDI: 0000000000000003
RBP: 00007f95ad632d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f95ad816128 R14: 00007f95ad816090 R15: 00007ffd81adee48
INFO: task syz.3.576:8646 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.3.576 state:D stack:28104 pid:8646 tgid:8641 ppid:5634 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:820
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
nfsd_umount+0x3b/0x60 fs/nfsd/nfsctl.c:1364
deactivate_locked_super+0xc1/0x1b0 fs/super.c:476
deactivate_super fs/super.c:509 [inline]
deactivate_super+0xe7/0x110 fs/super.c:505
cleanup_mnt+0x21f/0x450 fs/namespace.c:1312
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:67 [inline]
exit_to_user_mode_loop+0x157/0x670 kernel/entry/common.c:98
__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: 0033:0x7f64a379ce59
RSP: 002b:00007f64a46ba028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: fffffffffffffffe RBX: 00007f64a3a16180 RCX: 00007f64a379ce59
RDX: 0000200000000140 RSI: 00002000000000c0 RDI: 0000000000000000
RBP: 00007f64a3832d6f R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000000f R11: 0000000000000246 R12: 0000000000000000
R13: 00007f64a3a16218 R14: 00007f64a3a16180 R15: 00007ffeb296c898
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e7e5360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e7e5360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e7e5360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by getty/5392:
#0: ffff8880330ba0a0 (&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+0x419/0x14f0 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/5633:
#0: ffff88802c9160d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88802c9160d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88802c9160d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff88802c9160d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ec623e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/5637:
#0: ffff88802d3620d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88802d3620d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88802d3620d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff88802d3620d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ec623e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz.2.539/8427:
#0: ffffffff906b4a88 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec623e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1948
2 locks held by syz.2.539/8428:
#0: ffffffff906b4a88 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec623e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1948
2 locks held by syz.3.576/8646:
#0: ffff88802b4f00d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88802b4f00d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88802b4f00d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff88802b4f00d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ec623e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/8711:
#0: ffff888036c580d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888036c580d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888036c580d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff888036c580d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ec623e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/8891:
#0: ffff88802ae320d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88802ae320d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88802ae320d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff88802ae320d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ec623e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/8942:
#0: ffff88805b2320d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88805b2320d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88805b2320d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff88805b2320d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ec623e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/9078:
#0: ffff888025e4e0d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888025e4e0d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888025e4e0d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff888025e4e0d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ec623e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/9275:
#0: ffff888043eea0d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888043eea0d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888043eea0d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff888043eea0d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ec623e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/9557:
#0: ffff88801bb600d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88801bb600d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88801bb600d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff88801bb600d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ec623e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz.8.747/9704:
#0: ffff88807d2260d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88807d2260d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88807d2260d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff88807d2260d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ec623e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/9722:
#0: ffff888042bc00d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888042bc00d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888042bc00d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff888042bc00d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ec623e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
4 locks held by kworker/u10:7/10484:
#0: ffff88801c6a6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289
#1: ffffc9000599fd08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290
#2: ffffffff905ed8c8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:673
#3: ffffffff8e7f0ea8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
2 locks held by syz.4.960/10896:
#0: ffffffff905ed8c8 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff8e7f0ea8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 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 04/18/2026
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:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
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