INFO: task syz-executor:20932 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22256 pid:20932 tgid:20932 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7376
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
 nfsd_umount+0x41/0x60 fs/nfsd/nfsctl.c:1372
 deactivate_locked_super+0xbe/0x110 fs/super.c:586
 cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317
 task_work_run+0x1d9/0x270 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:70 [inline]
 exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101
 __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:343 [inline]
 do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f89eb79f397
RSP: 002b:00007fffd3bd9a08 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f89eb8344bb RCX: 00007f89eb79f397
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffd3bd9ac0
RBP: 00007fffd3bd9ac0 R08: 00007fffd3bdaac0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffd3bdab50
R13: 00007f89eb8344bb R14: 000000000019853b R15: 00007fffd3bdab90
 </TASK>

Showing all locks held in the system:
locks held by kworker/u8:1/13: 7, last CPU#1:
 #0: ffff88801c2ce140 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88801c2ce140 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88801c2ce140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff88801c2ce140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc90000127c40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90000127c40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90000127c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc90000127c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #2: ffffffff90246448 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:677
 #3: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xd0/0x760 net/core/dev.c:13285
 #4: ffff88801c2ccaa0 (&root->kernfs_supers_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3f/0x140 fs/kernfs/dir.c:1791
 #5: ffff88801c2cc980 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x4e/0x140 fs/kernfs/dir.c:1792
 #6: ffff88801c2cca10 (&root->kernfs_iattr_rwsem){++++}-{4:4}, at: __kernfs_remove+0x174/0x8e0 fs/kernfs/dir.c:1558
locks held by khungtaskd/32: 1, last CPU#0:
 #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 kworker/u8:12/3319: 2, on CPU#1:
 #0: ffff88801b0a4140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88801b0a4140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88801b0a4140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff88801b0a4140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc9000ee3fc40 ((reaper_work).work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc9000ee3fc40 ((reaper_work).work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc9000ee3fc40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc9000ee3fc40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
locks held by dhcpcd/5277: 2, on CPU#1:
 #0: ffff88802a2ba6e8 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xf4/0x7b0 net/netlink/af_netlink.c:2429
 #1: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dump_ifinfo+0xa74/0x14a0 net/core/rtnetlink.c:2618
locks held by getty/5371: 2, on CPU#1:
 #0: ffff88802976c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/u8:4/13715: 3, on CPU#1:
 #0: ffff88801b0a4140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88801b0a4140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88801b0a4140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff88801b0a4140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc9000474fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc9000474fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc9000474fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc9000474fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #2: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
locks held by syz-executor/20932: 2, on CPU#1:
 #0: ffff888055f0a0e8 (&type->s_umount_key#108){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline]
 #0: ffff888055f0a0e8 (&type->s_umount_key#108){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
 #0: ffff888055f0a0e8 (&type->s_umount_key#108){+.+.}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613
 #1: ffffffff8f09f7c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by syz-executor/22501: 1, on CPU#0:
 #0: ffffffff8ed62c68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #0: ffffffff8ed62c68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:966
locks held by syz.7.4908/23495: 2, on CPU#0:
 #0: ffffffff902c5e08 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff8f09f7c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2b9/0xc30 fs/nfsd/nfsctl.c:1690
locks held by syz-executor/23759: 4, last CPU#0:
 #0: ffffffff8ee36650 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1542 [inline]
 #0: ffffffff8ee36650 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x10a/0x480 kernel/fork.c:1595
 #1: ffff888077b67180 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
 #1: ffff888077b67180 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x195/0x1dc0 mm/mmap.c:1716
 #2: ffff88801b097180 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:552 [inline]
 #2: ffff88801b097180 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x221/0x1dc0 mm/mmap.c:1723
 #3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290
locks held by syz-executor/26925: 1, on CPU#1:
 #0: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
 #0: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4219
locks held by syz.2.5819/27087: 2, last CPU#1:
 #0: ffff8880759fd900 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
 #0: ffff8880759fd900 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299
 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290
locks held by syz.4.5827/27079: 2, last CPU#1:
 #0: ffff88801c2fa460 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
 #0: ffff88801c2fa460 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
 #1: ffff8880361ba0b0 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #1: ffff8880361ba0b0 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3430

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

NMI backtrace for cpu 0
CPU: 0 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 27079 Comm: syz.4.5827 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
RIP: 0010:clear_pages arch/x86/include/asm/page_64.h:103 [inline]
RIP: 0010:clear_highpages_kasan_tagged mm/page_alloc.c:1225 [inline]
RIP: 0010:post_alloc_hook+0x115/0x250 mm/page_alloc.c:1869
Code: 48 c1 e8 03 42 80 3c 28 00 74 0c 48 c7 c7 00 0f 6e 8e e8 ce da 0e 00 4c 03 25 d7 f9 44 0c 44 89 f9 48 c1 e1 0c 31 c0 4c 89 e7 <f3> aa 0f 1f 44 00 00 e8 df a2 0e 00 e9 c4 00 00 00 e9 d3 00 00 00
RSP: 0018:ffffc900055d74e0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000000005a0
RDX: 0000000000000200 RSI: 0000000000000000 RDI: ffff8880705f9a60
RBP: 0000000000140cca R08: ffffffff907a627f R09: ffffed100e0bf200
R10: dffffc0000000000 R11: fffffbfff20f4c50 R12: ffff8880705f9000
R13: dffffc0000000000 R14: ffffea0001c17e40 R15: 0000000000000001
FS:  00007fafebcd56c0(0000) GS:ffff888124dc8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7e86757e20 CR3: 0000000026952000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436
 alloc_pages_mpol+0x21e/0x390 mm/mempolicy.c:2486
 folio_alloc_mpol_noprof+0x39/0x160 mm/mempolicy.c:2505
 shmem_alloc_folio mm/shmem.c:1933 [inline]
 shmem_alloc_and_add_folio+0x43e/0xf60 mm/shmem.c:1975
 shmem_get_folio_gfp+0x5da/0x16d0 mm/shmem.c:2528
 shmem_get_folio mm/shmem.c:2634 [inline]
 shmem_write_begin+0x16c/0x330 mm/shmem.c:3265
 generic_perform_write+0x2d5/0x8f0 mm/filemap.c:4374
 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3440
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x612/0xba0 fs/read_write.c:687
 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: 0033:0x7fafead5e98e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007fafebcd4da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fafebcd56c0 RCX: 00007fafead5e98e
RDX: 00000000013bd7ef RSI: 00007fafe0a00000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007fafebcd4ee0 R14: 00007fafebcd4ea0 R15: 00007fafe0a00000
 </TASK>