INFO: task syz.0.27993:6960 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.27993     state:D stack:26768 pid:6960  tgid:6958  ppid:5620   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7f7/0x1550
 nfsd_nl_listener_set_doit+0x141/0x1670
 genl_family_rcv_msg_doit+0x22a/0x330
 genl_rcv_msg+0x61c/0x7a0
 netlink_rcv_skb+0x232/0x4b0
 genl_rcv+0x28/0x40
 netlink_unicast+0x75c/0x8e0
 netlink_sendmsg+0x813/0xb40
 ____sys_sendmsg+0x972/0x9f0
 ___sys_sendmsg+0x2a5/0x360
 __x64_sys_sendmsg+0x1bd/0x2a0
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff6e079cdd9
RSP: 002b:00007ff6e1658028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff6e0a16090 RCX: 00007ff6e079cdd9
RDX: 0000000000000000 RSI: 00002000000001c0 RDI: 0000000000000007
RBP: 00007ff6e0832d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff6e0a16128 R14: 00007ff6e0a16090 R15: 00007ffc1b154cb8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/35:
 #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5441:
 #0: ffff8881752e70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
2 locks held by syz.0.27993/6959:
 #0: ffffffff8fe3fac8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670
2 locks held by syz.0.27993/6960:
 #0: ffffffff8fe3fac8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670

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

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+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xfd3/0x1030
 kthread+0x388/0x470
 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: 14211 Comm: syz.1.29934 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:lock_is_held_type+0xec/0x150
Code: 0f 95 c0 31 db 39 c5 0f 94 c3 eb 05 bb 01 00 00 00 48 c7 c7 f1 f6 21 8e e8 31 19 00 00 b8 ff ff ff ff 65 0f c1 05 74 1d 90 07 <83> f8 01 75 25 9c 58 a9 00 02 00 00 75 39 41 f7 c4 00 02 00 00 74
RSP: 0018:ffffc90009187748 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8e21f6f1 RDI: ffffffff8c28ade0
RBP: 00000000ffffffff R08: ffffffff9030df0f R09: 1ffffffff2061be1
R10: dffffc0000000000 R11: fffffbfff2061be2 R12: 0000000000000046
R13: ffff8881ed95bb00 R14: ffffffff8e95cdc0 R15: 0000000000000001
FS:  00005555860b6500(0000) GS:ffff88818dc87000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f75ef4f000 CR3: 000000016d736000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 rcu_read_lock_any_held+0x48/0x90
 pick_next_task_fair+0x407/0x1ab0
 __pick_next_task+0xe6/0x480
 __schedule+0x974/0x5680
 schedule+0x164/0x360
 do_nanosleep+0x1c2/0x620
 hrtimer_nanosleep+0x18f/0x3a0
 __se_sys_clock_nanosleep+0x35b/0x3b0
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f270495d60e
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:00007ffc4a8714c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 00005555860b6500 RCX: 00007f270495d60e
RDX: 00007ffc4a871520 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f2704c17da0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000256d90
R13: 00007f2704c1618c R14: 0000000000256af7 R15: 00007f2704c16180
 </TASK>
