INFO: task syz.4.268:6503 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.4.268       state:D stack:27432 pid:6503  tgid:6499  ppid:5627   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5526 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7277
 __schedule_loop kernel/sched/core.c:7354 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7369
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7426
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 nfsd_nrthreads+0x4c/0xd0 fs/nfsd/nfssvc.c:252
 write_threads+0x216/0x610 fs/nfsd/nfsctl.c:445
 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: 0033:0x7f5fb019e159
RSP: 002b:00007f5fb0fff028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5fb0426090 RCX: 00007f5fb019e159
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f5fb023506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5fb0426128 R14: 00007f5fb0426090 R15: 00007ffca2601028
 </TASK>

Showing all locks held in the system:
locks held by kworker/u8:1/13: 3, last CPU#0:
 #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: ffffc90000127c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90000127c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90000127c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc90000127c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #2: ffff888052b91258 (&devlink->lock_key#8){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb40 drivers/net/netdevsim/dev.c:834
locks held by khungtaskd/32: 1, last CPU#0:
 #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by getty/5363: 2, on CPU#0:
 #0: ffff8880345530a0 (&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 kworker/u8:9/5795: 5, last CPU#1:
 #0: ffff888031827940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff888031827940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff888031827940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff888031827940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc90004dffc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90004dffc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90004dffc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc90004dffc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #2: ffffffff90253400 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline]
 #2: ffffffff90253400 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x116/0x15c0 net/ipv6/addrconf.c:4230
 #3: ffff888051c41530 (&idev->mc_lock){+.+.}-{4:4}, at: __ipv6_dev_mc_inc+0x4e/0xaf0 net/ipv6/mcast.c:963
 #4: ffffffff8ee90160 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:316 [inline]
 #4: ffffffff8ee90160 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4636 [inline]
 #4: ffffffff8ee90160 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:4974 [inline]
 #4: ffffffff8ee90160 (fs_reclaim){+.+.}-{0:0}, at: kmem_cache_alloc_node_noprof+0x5f/0x610 mm/slub.c:5068
locks held by syz.4.268/6500: 3, on CPU#0:
 #0: ffff8880203c50b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
 #1: ffff888078d12460 (sb_writers#32){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
 #1: ffff888078d12460 (sb_writers#32){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
 #2: ffffffff8f09f580 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:867
locks held by syz.4.268/6503: 3, on CPU#0:
 #0: ffff8880252cdb30 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
 #1: ffff888078d12460 (sb_writers#32){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
 #1: ffff888078d12460 (sb_writers#32){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
 #2: ffffffff8f09f580 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nrthreads+0x4c/0xd0 fs/nfsd/nfssvc.c:252
locks held by syz-executor/8738: 4, last CPU#1:
 #0: ffffffff8ee363b0 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1542 [inline]
 #0: ffffffff8ee363b0 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x10f/0x480 kernel/fork.c:1595
 #1: ffff8880799c1078 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
 #1: ffff8880799c1078 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x195/0x1dc0 mm/mmap.c:1716
 #2: ffff88807f1583b8 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:552 [inline]
 #2: ffff88807f1583b8 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x221/0x1dc0 mm/mmap.c:1723
 #3: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #3: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #3: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290
locks held by syz-executor/9795: 1, on CPU#0:
 #0: ffffffff90253400 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff90253400 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
 #0: ffffffff90253400 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4219
locks held by syz.7.1474/10340: 2, last CPU#0:
 #0: ffff888030c8a0a0 (&ctx->uring_lock){+.+.}-{4:4}, at: __do_sys_io_uring_enter io_uring/io_uring.c:2636 [inline]
 #0: ffff888030c8a0a0 (&ctx->uring_lock){+.+.}-{4:4}, at: __se_sys_io_uring_enter+0x350/0x1bb0 io_uring/io_uring.c:2586
 #1: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
 #1: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by syz.3.1476/10345: 2, last CPU#0:
 #0: ffff88807e421078 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
 #0: ffff88807e421078 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299
 #1: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290
locks held by kworker/u8:11/10352: 2, on CPU#0:
 #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: ffffc90006797c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90006797c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90006797c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc90006797c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
locks held by syz.2.1479/10364: 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: ffff888026ba5d00 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #1: ffff888026ba5d00 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3430
locks held by modprobe/10366: 4, last CPU#0:
 #0: ffff888032eefd08 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310
 #1: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: do_fault_around mm/memory.c:5957 [inline]
 #1: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: do_read_fault mm/memory.c:5991 [inline]
 #1: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: do_fault mm/memory.c:6134 [inline]
 #1: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: do_pte_missing+0x140c/0x34b0 mm/memory.c:4700
 #2: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #2: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #2: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: filemap_map_pages+0x1d1/0x2170 mm/filemap.c:3921
 #3: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #3: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #3: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290
locks held by cmp/10367: 3, last CPU#0:
 #0: ffff888036a2b6b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:544 [inline]
 #0: ffff888036a2b6b8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2d8/0x9f0 mm/mmap.c:1323
 #1: ffffffff8f58b3c0 (fill_pool_map-wait-type-override){+.+.}-{3:3}, at: debug_objects_fill_pool lib/debugobjects.c:779 [inline]
 #1: ffffffff8f58b3c0 (fill_pool_map-wait-type-override){+.+.}-{3:3}, at: debug_object_activate+0x364/0x420 lib/debugobjects.c:869
 #2: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #2: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #2: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
 #2: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026
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: 10364 Comm: syz.2.1479 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026
RIP: 0010:folio_objcg include/linux/memcontrol.h:398 [inline]
RIP: 0010:folio_memcg+0x67/0x1c0 include/linux/memcontrol.h:434
Code: c1 e8 03 42 0f b6 04 20 84 c0 0f 85 00 01 00 00 41 0f b6 6f 03 c1 e5 18 bf 00 00 00 f5 89 ee e8 cf fe b9 ff 81 fd 00 00 00 f5 <0f> 84 24 01 00 00 48 89 de 48 83 e6 01 31 ff e8 75 ff b9 ff 48 89
RSP: 0018:ffffc90003277580 EFLAGS: 00000006
RAX: ffffffff820dd8b1 RBX: ffff888025996a00 RCX: ffff88802e45ddc0
RDX: 0000000000000002 RSI: 00000000ff000000 RDI: 00000000f5000000
RBP: 00000000ff000000 R08: ffffea0001236147 R09: 1ffffd4000246c28
R10: dffffc0000000000 R11: fffff94000246c29 R12: dffffc0000000000
R13: 1ffff11003b57bd0 R14: ffffea0001236140 R15: ffffea0001236170
FS:  00007f405c1e46c0(0000) GS:ffff888124dce000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4051e00000 CR3: 000000001fbfb000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 folio_matches_lruvec include/linux/memcontrol.h:1544 [inline]
 lruvec_add_folio include/linux/mm_inline.h:351 [inline]
 lru_add+0x865/0xe90 mm/folio.c:148
 folio_batch_move_lru+0x6e9/0xa60 mm/folio.c:194
 __folio_batch_add_and_move+0x510/0xc50 mm/folio.c:225
 shmem_alloc_and_add_folio+0xcc2/0xf60 mm/shmem.c:2034
 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: 0033:0x7f405b35e98e
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:00007f405c1e3da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f405c1e46c0 RCX: 00007f405b35e98e
RDX: 0000000001000000 RSI: 00007f4051000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f405c1e3ee0 R14: 00007f405c1e3ea0 R15: 00007f4051000000
 </TASK>