INFO: task syz.9.2052:11269 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.2052      state:D stack:24792 pid:11269 tgid:11268 ppid:10989  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7fe/0x1300
 nfsd_nl_listener_get_doit+0x10a/0x5e0
 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: 0033:0x7ff64ff9c799
RSP: 002b:00007ff650db8028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff650215fa0 RCX: 00007ff64ff9c799
RDX: 0000000000008040 RSI: 0000200000000140 RDI: 0000000000000005
RBP: 00007ff650032c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff650216038 R14: 00007ff650215fa0 R15: 00007ffd4563c198
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e75e3e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/0:2/782:
 #0: ffff888100692d48 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830
 #1: ffffc900045d7c40 ((work_completion)(&(&ssp->srcu_sup->work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830
 #2: ffffffff8e7bd3f8 (&ssp->srcu_sup->srcu_gp_mutex){+.+.}-{4:4}, at: process_srcu+0x6e/0x1220
2 locks held by getty/5634:
 #0: ffff888111e550a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900032b02f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
1 lock held by udevd/8072:
 #0: ffff88816a285358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by udevd/8074:
 #0: ffff88816a22f358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
2 locks held by syz.4.1594/9940:
 #0: ffffffff8fc3ab70 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8ea857e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670
1 lock held by syz-executor/10991:
 #0: ffffffff8e764678 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
2 locks held by syz.9.2052/11269:
 #0: ffffffff8fc3ab70 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8ea857e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x10a/0x5e0
1 lock held by syz.5.4129/16465:
 #0: ffffffff8e7ce888 (event_mutex){+.+.}-{4:4}, at: perf_trace_destroy+0x2e/0x150
4 locks held by syz.5.4129/16466:
1 lock held by syz.2.4130/16467:
 #0: ffffffff8e7ce888 (event_mutex){+.+.}-{4:4}, at: perf_trace_destroy+0x2e/0x150

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

NMI backtrace for cpu 0
CPU: 0 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5846 Comm: kworker/u8:3 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
Workqueue: bat_events batadv_purge_orig
RIP: 0010:batadv_purge_orig_ref+0x138a/0x1460
Code: eb 12 e8 39 2b 4b f6 48 8b bc 24 a0 00 00 00 e8 3c 1e 36 00 48 8b 84 24 98 00 00 00 42 0f b6 04 38 84 c0 48 8b 54 24 48 75 28 <48> 8b 74 24 68 48 ff c6 8b 02 48 89 74 24 68 48 39 c6 73 31 e8 fd
RSP: 0018:ffffc9000678f960 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff8881ba8b4870 RCX: ffff888114410000
RDX: ffff8881a42a9950 RSI: 000000000000010e RDI: 0000000000000000
RBP: ffffc9000678fae0 R08: ffffffff90118bb7 R09: 1ffffffff2023176
R10: dffffc0000000000 R11: ffffffff8b7a1330 R12: ffff8881bc900f08
R13: ffff888110970318 R14: 1ffff1103751690e R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8882a9463000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f76c00b66f9 CR3: 000000000e54c000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 batadv_purge_orig+0x19/0x60
 process_scheduled_works+0xb02/0x1830
 worker_thread+0xa50/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 ret_from_fork_asm+0x1a/0x30
 </TASK>
