INFO: task syz.3.1444:10784 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1444      state:D stack:28552 pid:10784 tgid:10779 ppid:5619   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5526 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7276
 __schedule_loop kernel/sched/core.c:7353 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7368
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7425
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 write_versions+0x95/0xe30 fs/nfsd/nfsctl.c:708
 nfsctl_transaction_write+0x10f/0x160 fs/nfsd/nfsctl.c:114
 vfs_write+0x296/0xba0 fs/read_write.c:685
 ksys_write+0x150/0x270 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb3d659e159
RSP: 002b:00007fb3d73e2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fb3d6826090 RCX: 00007fb3d659e159
RDX: 0000000000000001 RSI: 0000200000000340 RDI: 0000000000000004
RBP: 00007fb3d663503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb3d6826128 R14: 00007fb3d6826090 R15: 00007fff7d611778
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/32: 1, last CPU#1:
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by getty/5366: 2, on CPU#0:
 #0: ffff8880352d60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz.3.1444/10781: 3, on CPU#1:
 #0: ffff88805756d7b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
 #1: ffff888034c94460 (sb_writers#27){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
 #1: ffff888034c94460 (sb_writers#27){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
 #2: ffffffff8f09f500 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:867
locks held by syz.3.1444/10784: 3, on CPU#1:
 #0: ffff888034a7d0b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
 #1: ffff888034c94460 (sb_writers#27){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
 #1: ffff888034c94460 (sb_writers#27){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
 #2: ffffffff8f09f500 (nfsd_mutex){+.+.}-{4:4}, at: write_versions+0x95/0xe30 fs/nfsd/nfsctl.c:708

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd7/0x1030 kernel/hung_task.c:561
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: ac 8f 02 e9 5e 60 2b f5 cc cc cc 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 33 a1 24 00 fb f4 <e9> 37 60 2b f5 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8ea07ca0 EFLAGS: 00000246
RAX: 0000000000175e05 RBX: ffffffff819baed0 RCX: 8000000000000001
RDX: 0000000000000001 RSI: ffffffff8e476008 RDI: ffffffff8c6d9c80
RBP: ffffffff8ea07d78 R08: ffff8880b8633a1b R09: 1ffff110170c6743
R10: dffffc0000000000 R11: ffffed10170c6744 R12: 0000000000000000
R13: 1ffffffff1d51df8 R14: 1ffffffff1d40f9c R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888124cd2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f3e76db168 CR3: 000000000eb48000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/kernel/process.c:767 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:768
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x2e0/0x540 kernel/sched/idle.c:355
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454
 rest_init+0x378/0x3a0 init/main.c:727
 start_kernel+0x392/0x3e0 init/main.c:1185
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x137/0x1b0 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x157
 </TASK>