INFO: task syz.3.21773:3311 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.21773     state:D stack:27344 pid:3311  tgid:3307  ppid:1064   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7fe/0x1300
 nfsd_nl_threads_get_doit+0x1c0/0x790
 genl_family_rcv_msg_doit+0x22a/0x330
 genl_rcv_msg+0x61c/0x7a0
 netlink_rcv_skb+0x232/0x4b0
 genl_rcv+0x28/0x40
 netlink_unicast+0x80f/0x9b0
 netlink_sendmsg+0x813/0xb40
 ____sys_sendmsg+0x972/0x9f0
 ___sys_sendmsg+0x2a5/0x360
 __x64_sys_sendmsg+0x1bd/0x2a0
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa357d9cdd9
RSP: 002b:00007fa358bcd028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa358016180 RCX: 00007fa357d9cdd9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000009
RBP: 00007fa357e32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa358016218 R14: 00007fa358016180 R15: 00007ffec4228ec8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5635:
 #0: ffff88816f7de0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
1 lock held by syz-executor/5783:
2 locks held by syz.1.21033/459:
 #0: ffffffff8fc3e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8ea86b88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670
2 locks held by syz.3.21773/3311:
 #0: ffffffff8fc3e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8ea86b88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c0/0x790
3 locks held by kworker/u8:5/5560:
 #0: ffff8881066d9948 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc90008b7fc40 ((work_completion)(&(rwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffffffff8fbd0b88 (rtnl_mutex){+.+.}-{4:4}, at: mall_destroy_work+0x16/0x30
3 locks held by syz.0.23346/9090:
 #0: ffffffff8fc3e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffff888106b6a6f0 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0
 #2: ffffffff8ea86b88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xdc/0x1410
2 locks held by syz.2.23710/10478:
 #0: ffffffff8fbd0b88 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
 #1: ffffffff8e7648f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
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+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xfd9/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 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: 5783 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:unwind_next_frame+0x214/0x23c0
Code: ef 08 8b 15 5e b1 a4 0c 8d 42 ff 44 39 f8 0f 86 78 04 00 00 44 89 f8 4c 8d 2c 85 7c 06 53 91 4c 89 e8 48 c1 e8 03 0f b6 04 28 <84> c0 48 89 eb 0f 85 25 1c 00 00 45 8b 6d 00 44 89 f8 ff c0 48 8d
RSP: 0018:ffffc9000600ed78 EFLAGS: 00000a07
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000080000000
RDX: 00000000000ab3ac RSI: ffffffff8c27d560 RDI: ffffffff8c27d520
RBP: dffffc0000000000 R08: ffffffff81769a55 R09: ffffffff8e75e5e0
R10: ffffc9000600ee98 R11: ffffffff81b0eba0 R12: ffffffff81859a47
R13: ffffffff91551ce4 R14: ffffc9000600ee48 R15: 000000000000859a
FS:  0000555558739540(0000) GS:ffff88818de54000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9efa1ea4c0 CR3: 00000001b3ae2000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 save_stack+0x122/0x230
 __reset_page_owner+0x71/0x1f0
 free_unref_folios+0xed5/0x16d0
 folios_put_refs+0x789/0x8d0
 free_pages_and_swap_cache+0x2e7/0x5b0
 tlb_flush_mmu+0x6d3/0xa30
 unmap_page_range+0x3c1d/0x48f0
 unmap_vmas+0x48f/0x6a0
 exit_mmap+0x280/0xa10
 __mmput+0x118/0x430
 exit_mm+0x168/0x220
 do_exit+0x6a2/0x23c0
 do_group_exit+0x21b/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x221a/0x2240
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f529379cdd9
Code: Unable to access opcode bytes at 0x7f529379cdaf.
RSP: 002b:00007ffcc0bbfbc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f529384dd71 RCX: 00007f529379cdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043
RBP: 00007f529384dd8f R08: 0000000000000000 R09: 00007ffcc0bbfcec
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009
R13: 00007ffcc0bbfcec R14: 00007ffcc0bbfd80 R15: 0000000000000000
 </TASK>
