INFO: task syz.3.1968:14800 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.3.1968 state:D stack:29032 pid:14800 tgid:14799 ppid:5824 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xfe4/0x5e10 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
nfsd_umount+0x3b/0x60 fs/nfsd/nfsctl.c:1353
deactivate_locked_super+0xc1/0x1b0 fs/super.c:474
deactivate_super fs/super.c:507 [inline]
deactivate_super+0xe7/0x110 fs/super.c:503
cleanup_mnt+0x21f/0x450 fs/namespace.c:1318
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:44 [inline]
exit_to_user_mode_loop+0x100/0x4b0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4ea/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fced879aeb9
RSP: 002b:00007fced9595028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: fffffffffffffffe RBX: 00007fced8a15fa0 RCX: 00007fced879aeb9
RDX: 0000200000000080 RSI: 0000200000000040 RDI: 0000000000000000
RBP: 00007fced8808c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fced8a16038 R14: 00007fced8a15fa0 R15: 00007ffd9829a9f8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by getty/6641:
#0: ffff88803608d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900190fb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
3 locks held by kworker/u8:11/10937:
#0: ffff88814c9bd948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc90019797c98 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffffffff903f5868 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff903f5868 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4734
1 lock held by syz.1.1188/11147:
5 locks held by kworker/u8:27/14203:
#0: ffff88801c29f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc900046d7c98 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffffffff903dcf30 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xab/0x830 net/core/net_namespace.c:670
#3: ffffffff903f5868 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
#3: ffffffff903f5868 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248
#4: ffffffff8e5ef8f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
3 locks held by kworker/u8:29/14205:
#0: ffff8880b843add8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:647 [inline]
#0: ffff8880b843add8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:632
#1: ffff8880b8524608 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline]
#1: ffff8880b8524608 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2b6f/0x5e10 kernel/sched/core.c:6861
#2: ffff888030a98788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6360 [inline]
#2: ffff888030a98788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0x92/0x560 net/wireless/core.c:424
2 locks held by syz.2.1963/14770:
#0: ffffffff904a26d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8ea472a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b20 fs/nfsd/nfsctl.c:1886
2 locks held by syz.3.1968/14800:
#0: ffff888032a200e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888032a200e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888032a200e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff888032a200e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503
#1: ffffffff8ea472a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
2 locks held by syz.5.1973/14828:
#0: ffff888079f7c0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888079f7c0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888079f7c0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff888079f7c0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503
#1: ffffffff8ea472a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
1 lock held by syz.8.2053/15287:
2 locks held by syz.4.2060/15308:
#0: ffff8880233140e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880233140e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880233140e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff8880233140e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503
#1: ffffffff8ea472a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
2 locks held by syz-executor/15430:
#0: ffff88806a2ec0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88806a2ec0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88806a2ec0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88806a2ec0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503
#1: ffffffff8ea472a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
2 locks held by syz.7.2227/16331:
#0: ffff88802e6c80e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88802e6c80e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88802e6c80e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88802e6c80e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503
#1: ffffffff8ea472a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
2 locks held by syz.6.2234/16395:
=============================================
NMI backtrace for cpu 1
CPU: 1 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 01/24/2026
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:161 [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:346 [inline]
watchdog+0xcc3/0xfe0 kernel/hung_task.c:515
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: a6 7a 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 63 6c 17 00 fb f4 fc 31 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e207e00 EFLAGS: 00000242
RAX: 0000000000465e75 RBX: ffffffff8e297ac0 RCX: ffffffff8b7414b5
RDX: 0000000000000000 RSI: ffffffff8dc41a8e RDI: ffffffff8bfa3320
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed101708673d
R10: ffff8880b84339eb R11: 0000000000000000 R12: fffffbfff1c52f58
R13: 0000000000000000 R14: ffffffff90b76fd0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881245e2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2dc83e4198 CR3: 000000006fb98000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x35b/0x4b0 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
rest_init+0x251/0x260 init/main.c:757
start_kernel+0x47a/0x480 init/main.c:1206
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x122/0x130 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148