INFO: task syz.8.2699:12677 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.8.2699      state:D stack:27432 pid:12677 tgid:12675 ppid:10817  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d4/0x5630
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 write_threads+0x39d/0x5a0
 nfsctl_transaction_write+0x10f/0x160
 vfs_write+0x296/0xba0
 ksys_write+0x150/0x270
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f84cf59e159
RSP: 002b:00007f84cd7f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f84cf826090 RCX: 00007f84cf59e159
RDX: 0000000000000002 RSI: 0000200000000700 RDI: 0000000000000003
RBP: 00007f84cf63506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f84cf826128 R14: 00007f84cf826090 R15: 00007fff1fdf18f8
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/35: 1, last CPU#1:
 #0: ffffffff8eb5a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
locks held by kworker/0:4/5671: 6, on CPU#0:
 #0: ffff888104acdd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa1a/0x14c0
 #1: ffffc90004ef7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa1a/0x14c0
 #2: ffff88817027f1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30
 #3: ffff88810fc671d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xfc/0x9a0
 #4: ffff8881094861a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880
 #5: ffffffff8eb602b8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530
locks held by syz.8.2699/12676: 3, on CPU#0:
 #0: ffff88810cccb6f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: ffff888111e44460 (sb_writers#31){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0
 #2: ffffffff8ee8fbe0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10
locks held by syz.8.2699/12677: 3, on CPU#1:
 #0: ffff888174094ef0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: ffff888111e44460 (sb_writers#31){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0
 #2: ffffffff8ee8fbe0 (nfsd_mutex){+.+.}-{4:4}, at: write_threads+0x39d/0x5a0
locks held by syz.1.3586/15075: 2, on CPU#0:
 #0: ffffffff9009c7a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8ee8fbe0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_cache_flush_doit+0xb5/0x1b0
locks held by syz.6.4314/16902: 2, last CPU#0:
 #0: ffffffff8eb5a0e0 (rcu_read_lock){....}-{1:3}, at: find_lock_entries+0x12a/0xad0
 #1: ffff88816b2a11b0 (&lruvec->lru_lock){..-.}-{3:3}, at: filemap_remove_folio+0xe7/0x3a0

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 35 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17d/0x390
 sys_info+0x135/0x170
 watchdog+0xfd7/0x1030
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16902 Comm: syz.6.4314 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:__lock_acquire+0xa41/0x2cf0
Code: 83 3d 46 53 b5 0e 00 75 13 48 8d 3d 19 b0 b8 0e 48 c7 c6 82 c5 35 8e 67 48 0f b9 3a 90 31 c0 48 83 78 40 00 0f 84 62 1b 00 00 <48> 09 dd 41 8b 45 20 89 c1 81 e1 00 80 04 00 81 f9 00 00 04 00 0f
RSP: 0018:ffffc9000635ef78 EFLAGS: 00000082
RAX: ffffffff94151a88 RBX: 00000000fe09d4ff RCX: 00000000105209fd
RDX: 000000005a44979c RSI: 0000000086db7919 RDI: ffff88816929da00
RBP: 0ac0d5af00000000 R08: ffffffff8177710f R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb5a0e0 R12: ffff88816929e5a8
R13: ffff88816929e5a8 R14: ffff88816929da00 R15: 0000000000000000
FS:  00007f6e77a3f6c0(0000) GS:ffff88818d939000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6e76beb840 CR3: 00000001a1436000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x106/0x350
 unwind_next_frame+0xac/0x2550
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 save_stack+0x122/0x230
 __reset_page_owner+0x71/0x1f0
 free_unref_folios+0xd84/0x14a0
 folios_put_refs+0x9e9/0xb30
 shmem_undo_range+0x4e6/0x15d0
 shmem_evict_inode+0x280/0xa80
 evict+0x624/0xb50
 dentry_kill+0x1b9/0x880
 finish_dput+0x1a/0x260
 __fput+0x675/0xa50
 task_work_run+0x1d9/0x270
 exit_to_user_mode_loop+0x204/0x770
 do_syscall_64+0x328/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6e76b9e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6e77a3f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: 0000200000000000 RBX: 00007f6e76e25fa0 RCX: 00007f6e76b9e159
RDX: 000000000080000a RSI: 0000000000fbe000 RDI: 0000200000000000
RBP: 00007f6e76c3506b R08: ffffffffffffffff R09: 00000000d0fb8000
R10: 0000000000000031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6e76e26038 R14: 00007f6e76e25fa0 R15: 00007ffe9a046bc8
 </TASK>
