INFO: task syz-executor:12879 blocked for more than 143 seconds.
Tainted: G U W L XTNJ syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:24216 pid:12879 tgid:12879 ppid:1 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: 0033:0x7fbef359c117
RSP: 002b:00007ffcdec67a38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fbef360471f RCX: 00007fbef359c117
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcdec67af0
RBP: 00007ffcdec67af0 R08: 00007ffcdec68af0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcdec68b80
R13: 00007fbef360471f R14: 00000000000756b4 R15: 00007ffcdec68bc0
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/5583:
#0: ffff88814d6c50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/5822:
#0: ffff888029db40e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888029db40e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888029db40e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff888029db40e0 (&type->s_umount_key#55){+.+.}-{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/5831:
#0: ffff8880298860e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880298860e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880298860e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff8880298860e0 (&type->s_umount_key#55){+.+.}-{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 kworker/u8:27/9318:
#0: ffff888143e80948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc90004b7fc98 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
2 locks held by syz.0.1340/12557:
#0: ffffffff904a2690 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8ea472a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1596
2 locks held by syz-executor/12879:
#0: ffff88805867e0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88805867e0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88805867e0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88805867e0e0 (&type->s_umount_key#55){+.+.}-{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/13884:
#0: ffff888031ed00e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888031ed00e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888031ed00e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff888031ed00e0 (&type->s_umount_key#55){+.+.}-{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.6.1815/14995:
#0: ffff88807be5c0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88807be5c0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88807be5c0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88807be5c0e0 (&type->s_umount_key#55){+.+.}-{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.6.1815/14996:
#0: ffff88807be5c0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88807be5c0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: super_lock+0x1ca/0x3f0 fs/super.c:121
2 locks held by syz-executor/15065:
#0: ffff8880443b40e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880443b40e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880443b40e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff8880443b40e0 (&type->s_umount_key#55){+.+.}-{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.8.1847/15235:
#0: ffffffff904a2690 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8ea472a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1596
1 lock held by syz-executor/15482:
#0: ffffffff8e5ef8f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
2 locks held by syz.9.2053/16375:
1 lock held by syz.1.2071/16473:
#0: ffffffff8e5ef7c0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3816
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U W L XTNJ syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [W]=WARN, [L]=SOFTLOCKUP, [X]=AUX, [T]=RANDSTRUCT, [N]=TEST, [J]=FWCTL
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G U W L XTNJ syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [W]=WARN, [L]=SOFTLOCKUP, [X]=AUX, [T]=RANDSTRUCT, [N]=TEST, [J]=FWCTL
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x8/0x20 kernel/kcov.c:320
Code: 00 00 00 e9 2a fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 0c 24 <48> 89 f2 48 89 fe bf 07 00 00 00 e9 f8 fd ff ff 0f 1f 84 00 00 00
RSP: 0018:ffffc90000197d18 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 0000000000000010 RCX: ffffffff81f6e07c
RDX: 1ffff110170a51b4 RSI: 0000000000000010 RDI: 0000000000000000
RBP: ffff8880b8528da0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8880b8528e60 R14: ffffffff90b76fd0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8881246e3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000148d000 CR3: 0000000032782000 CR4: 00000000003526f0
Call Trace:
can_stop_idle_tick+0x8c/0x200 kernel/time/tick-sched.c:1194
tick_nohz_idle_stop_tick+0x799/0xe50 kernel/time/tick-sched.c:1238
cpuidle_idle_call kernel/sched/idle.c:189 [inline]
do_idle+0x356/0x4b0 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x148