INFO: task syz.2.20765:22035 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.20765     state:D stack:26832 pid:22035 tgid:22032 ppid:5589   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 nfsd_nl_svc_export_set_reqs_doit+0x132/0x1480
 genl_family_rcv_msg_doit+0x233/0x340
 genl_rcv_msg+0x614/0x7a0
 netlink_rcv_skb+0x226/0x4a0
 genl_rcv+0x28/0x40
 netlink_unicast+0x7bd/0x940
 netlink_sendmsg+0x813/0xb40
 sock_sendmsg_nosec+0x13a/0x180
 ____sys_sendmsg+0x54e/0x850
 ___sys_sendmsg+0x2a5/0x360
 __x64_sys_sendmsg+0x1b1/0x290
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbaf6b9e559
RSP: 002b:00007fbaf4db4028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fbaf6e26180 RCX: 00007fbaf6b9e559
RDX: 0000000000000000 RSI: 00002000000005c0 RDI: 000000000000000d
RBP: 00007fbaf6c358b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbaf6e26218 R14: 00007fbaf6e26180 R15: 00007ffec9b6f608
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/35: 1, last CPU#1:
 #0: ffffffff8fd5ce60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
locks held by getty/5419: 2, on CPU#0:
 #0: ffff88817a23c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034832e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
locks held by syz-executor/32760: 1, last CPU#0:
 #0: ffff888020238260 (sk_lock-AF_INET){+.+.}-{0:0}, at: do_ip_getsockopt+0x11a9/0x1d00
locks held by kworker/u8:7/29069: 2, last CPU#1:
 #0: ffff888177445940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90008817c40 ((work_completion)(&(&bat_priv->tt.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
locks held by kworker/1:15/11835: 4, last CPU#1:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc9000302fc40 ((work_completion)(&helper->damage_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffc9000302f770 (crtc_ww_class_acquire){+.+.}-{0:0}, at: drm_atomic_helper_dirtyfb+0x106/0xfd0
 #3: ffffc9000302f798 (crtc_ww_class_mutex){+.+.}-{4:4}, at: drm_atomic_helper_dirtyfb+0x106/0xfd0
locks held by syz.1.20627/21387: 2, on CPU#0:
 #0: ffffffff912cb9a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff900a4d40 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x53d/0x1ab0
locks held by syz.2.20765/22035: 2, on CPU#1:
 #0: ffffffff912cb9a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff900a4d40 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_svc_export_set_reqs_doit+0x132/0x1480
locks held by syz.5.21062/23307: 1, last CPU#0:
 #0: ffff888113fa3240 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x7a/0x1f0

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 35 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+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: 23307 Comm: syz.5.21062 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:_raw_spin_unlock_irqrestore+0x47/0x80
Code: f7 e8 7d e1 b4 f5 f7 c3 00 02 00 00 74 05 e8 00 2f e1 f5 9c 58 a9 00 02 00 00 75 29 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> b4 de a5 f5 65 48 8b 05 4c b0 a7 08 48 85 c0 74 18 5b 41 5e e9
RSP: 0018:ffffc90000007f40 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000283 RCX: 8000000000000102
RDX: 0000000000000002 RSI: ffffffff8e46e7e0 RDI: 0000000000000001
RBP: 0000000000000005 R08: ffffffff917ac17f R09: 1ffffffff22f582f
R10: dffffc0000000000 R11: fffffbfff22f5830 R12: 0000000000000009
R13: 0000000000000008 R14: ffff888120e28280 R15: 0000000000000100
FS:  00007f8eaccd86c0(0000) GS:ffff88818c4ab000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3c48bf0158 CR3: 0000000188054000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 handle_softirqs+0x226/0x860
 do_softirq+0x77/0xd0
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x100/0x140
 netlink_release+0xe3d/0x1a80
 __sock_release+0xa0/0x1f0
 sock_close+0x1c/0x30
 __fput+0x418/0xa50
 fput_close_sync+0x11f/0x240
 __x64_sys_close+0x7e/0x110
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8eabd5ed8e
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:00007f8eaccd6f38 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00007f8eaccd86c0 RCX: 00007f8eabd5ed8e
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000024
RBP: 0000000000000024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8eac026128 R14: 00007f8eac026090 R15: 00007ffd73245638
 </TASK>
