INFO: task syz-executor:5831 blocked for more than 143 seconds.
      Tainted: G     U              6.16.0-rc3-syzkaller-00042-g78f4e737a53e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:23544 pid:5831  tgid:5831  ppid:1      task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6878
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747
 nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
 nfsd_umount+0x48/0xe0 fs/nfsd/nfsctl.c:1386
 deactivate_locked_super+0xc1/0x1a0 fs/super.c:474
 deactivate_super fs/super.c:507 [inline]
 deactivate_super+0xde/0x100 fs/super.c:503
 cleanup_mnt+0x225/0x450 fs/namespace.c:1417
 task_work_run+0x14d/0x240 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:114
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x3f6/0x490 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffbeff8fc57
RSP: 002b:00007ffefb4b4618 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007ffbf0010925 RCX: 00007ffbeff8fc57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffefb4b46d0
RBP: 00007ffefb4b46d0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffefb4b5760
R13: 00007ffbf0010925 R14: 0000000000071ee2 R15: 00007ffefb4b57a0
 </TASK>
INFO: task syz.1.1252:11684 blocked for more than 144 seconds.
      Tainted: G     U              6.16.0-rc3-syzkaller-00042-g78f4e737a53e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1252      state:D stack:27464 pid:11684 tgid:11683 ppid:5833   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6878
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747
 nfsd_nl_listener_set_doit+0xdd/0x1a40 fs/nfsd/nfsctl.c:1922
 genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2534
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg net/socket.c:727 [inline]
 ____sys_sendmsg+0xa98/0xc70 net/socket.c:2566
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2620
 __sys_sendmsg+0x16d/0x220 net/socket.c:2652
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f913bb8e929
RSP: 002b:00007f91399f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f913bdb5fa0 RCX: 00007f913bb8e929
RDX: 0000000020000000 RSI: 0000200000005380 RDI: 0000000000000005
RBP: 00007f913bc10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f913bdb5fa0 R15: 00007fff10a25178
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e5c47c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e5c47c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e5c47c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770
2 locks held by syz-executor/5831:
 #0: ffff8880257ca0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff8880257ca0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff8880257ca0e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
 #0: ffff8880257ca0e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
 #1: ffffffff8e9ddd68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by kworker/u10:13/9066:
5 locks held by kworker/u10:34/9904:
2 locks held by syz.3.1220/11557:
 #0: ffffffff903f2ab0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffffffff8e9ddd68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629
2 locks held by syz.1.1252/11684:
 #0: ffffffff903f2ab0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffffffff8e9ddd68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xdd/0x1a40 fs/nfsd/nfsctl.c:1922
2 locks held by syz-executor/11786:
 #0: ffff88803f1200e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88803f1200e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88803f1200e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
 #0: ffff88803f1200e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
 #1: ffffffff8e9ddd68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz-executor/11865:
 #0: ffff8880323fe0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff8880323fe0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff8880323fe0e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
 #0: ffff8880323fe0e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
 #1: ffffffff8e9ddd68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz-executor/11888:
 #0: ffff88806fd5c0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88806fd5c0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88806fd5c0e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
 #0: ffff88806fd5c0e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
 #1: ffffffff8e9ddd68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz.0.1458/12744:
 #0: ffff88807c1260e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88807c1260e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88807c1260e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
 #0: ffff88807c1260e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
 #1: ffffffff8e9ddd68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by getty/13010:
 #0: ffff888035b1a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002ed62f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
3 locks held by syz.8.1699/13959:
1 lock held by syz.8.1724/14043:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G     U              6.16.0-rc3-syzkaller-00042-g78f4e737a53e #0 PREEMPT(full) 
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xf70/0x12c0 kernel/hung_task.c:470
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 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: 13959 Comm: syz.8.1699 Tainted: G     U              6.16.0-rc3-syzkaller-00042-g78f4e737a53e #0 PREEMPT(full) 
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:stack_trace_consume_entry+0x0/0x170 kernel/stacktrace.c:83
Code: e8 65 81 14 00 e9 36 ff ff ff 49 c7 c4 ea ff ff ff eb c7 e8 a2 91 d5 09 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 55 53 48 89 fb 48 83 c7
RSP: 0018:ffffc9002a9de5c0 EFLAGS: 00000286
RAX: ffffffff81a70c4e RBX: ffffc9002a9de5c8 RCX: ffffc9002a9de660
RDX: 1ffff9200553bcc2 RSI: ffffffff81a70c4e RDI: ffffc9002a9de688
RBP: ffffc9002a9de658 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 00000000000061a9 R12: ffffffff81a708c0
R13: ffffc9002a9de688 R14: 0000000000000000 R15: ffff88801e375a00
FS:  00007f9e177d56c0(0000) GS:ffff888124760000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000008ab000 CR3: 000000004156c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_stack_walk+0x88/0x100 arch/x86/kernel/stacktrace.c:27
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x160/0x1f0 mm/page_owner.c:156
 __set_page_owner+0x91/0x550 mm/page_owner.c:329
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2419
 folio_alloc_mpol_noprof+0x36/0x2f0 mm/mempolicy.c:2438
 shmem_alloc_folio+0x135/0x160 mm/shmem.c:1851
 shmem_alloc_and_add_folio+0x499/0xc20 mm/shmem.c:1890
 shmem_get_folio_gfp+0x67f/0x1600 mm/shmem.c:2536
 shmem_get_folio mm/shmem.c:2642 [inline]
 shmem_write_begin+0x160/0x300 mm/shmem.c:3292
 generic_perform_write+0x3d0/0x930 mm/filemap.c:4112
 shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3467
 __kernel_write_iter+0x317/0xa90 fs/read_write.c:619
 dump_emit_page fs/coredump.c:1112 [inline]
 dump_user_range+0x41f/0xb60 fs/coredump.c:1186
 elf_core_dump+0x288a/0x3a90 fs/binfmt_elf.c:2075
 do_coredump+0x399f/0x4f10 fs/coredump.c:950
 get_signal+0x22e3/0x26d0 kernel/signal.c:3019
 arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 irqentry_exit_to_user_mode+0x12a/0x270 kernel/entry/common.c:184
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x402000
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 002b:0000000000000089 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00007f9e19bb6080 RCX: 00007f9e1998e929
RDX: 0000000000000000 RSI: 0000000000000081 RDI: 0000000000000002
RBP: 00007f9e19a10b39 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9e19bb6080 R15: 00007ffe3e518368
 </TASK>