INFO: task syz.6.1308:10221 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.1308      state:D stack:25840 pid:10221 tgid:10217 ppid:8661   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 nfsd_nl_listener_get_doit+0x10a/0x5e0
 genl_family_rcv_msg_doit+0x215/0x300
 genl_rcv_msg+0x60e/0x790
 netlink_rcv_skb+0x208/0x470
 genl_rcv+0x28/0x40
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efca2b8eba9
RSP: 002b:00007efca39a6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007efca2dd5fa0 RCX: 00007efca2b8eba9
RDX: 0000000000008000 RSI: 0000200000006e40 RDI: 0000000000000008
RBP: 00007efca2c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efca2dd6038 R14: 00007efca2dd5fa0 R15: 00007fff84f57618
 </TASK>

Showing all locks held in the system:
2 locks held by rcu_tasks_trace/32:
 #0: ffffffff8e13ae50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{4:4}, at: rcu_tasks_one_gp+0xaf9/0xdf0
 #1: ffffffff8e13fbb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a120 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/1:1/47:
2 locks held by getty/5673:
 #0: ffff8881000ec0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
4 locks held by kworker/u8:2/5856:
2 locks held by syz.5.688/8305:
 #0: ffffffff8f59f8f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e418c48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2cb/0x960
2 locks held by syz.6.1308/10221:
 #0: ffffffff8f59f8f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e418c48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x10a/0x5e0
1 lock held by syz.3.2325/13405:
 #0: ffffffff8e19d6c8 (event_mutex){+.+.}-{4:4}, at: perf_trace_destroy+0x2e/0x150
1 lock held by syz.7.2326/13407:
 #0: ffffffff8e19d6c8 (event_mutex){+.+.}-{4:4}, at: perf_trace_destroy+0x2e/0x150
3 locks held by syz.4.2328/13415:
 #0: ffffffff99b146b0 (&pmus_srcu){.+.+}-{0:0}, at: class_srcu_constructor+0x2c/0x60
 #1: ffffffff99b146b0 (&pmus_srcu){.+.+}-{0:0}, at: perf_event_alloc+0xf61/0x2be0
 #2: ffffffff8e19d6c8 (event_mutex){+.+.}-{4:4}, at: perf_trace_init+0x50/0x2d0
5 locks held by syz.4.2328/13416:

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

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+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 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: 5831 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:native_apic_msr_write+0x39/0x50
Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 cc cc cc cc cc f3 0f 1e fa 89 f6 31 d2 e9 d2 fa 8e 03 66
RSP: 0018:ffffc900001e0e50 EFLAGS: 00000046
RAX: 000000000000b3e5 RBX: ffff888136623900 RCX: 0000000000000838
RDX: 0000000000000000 RSI: 000000000000b3e5 RDI: 0000000000000838
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81ae170e
R10: 0000000000000003 R11: ffffffff81704490 R12: 000000001000375d
R13: dffffc0000000000 R14: 000000000000b3e5 R15: 0000000000000020
FS:  000055556ded3500(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34214ff8 CR3: 000000010c012000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 lapic_next_event+0x11/0x20
 clockevents_program_event+0x1cf/0x360
 hrtimer_interrupt+0x620/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:lock_acquire+0x175/0x360
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 7b 5f 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000335f850 EFLAGS: 00000206
RAX: 9c2ce89944117e00 RBX: 0000000000000000 RCX: 9c2ce89944117e00
RDX: 0000000000000000 RSI: ffffffff8dba983d RDI: ffffffff8be33e80
RBP: ffffffff895aa16a R08: 0000000000000000 R09: ffffffff895aa16a
R10: ffffc9000335f9a0 R11: fffff5200066bf3a R12: 0000000000000000
R13: ffff8881105935d8 R14: 0000000000000001 R15: 0000000000000246
 _raw_spin_lock_bh+0x36/0x50
 lock_sock_nested+0x6a/0x100
 tcp_recvmsg+0x1fa/0x810
 inet_recvmsg+0x147/0x250
 sock_recvmsg+0x1a8/0x270
 sock_read_iter+0x231/0x2f0
 vfs_read+0x55a/0xa30
 ksys_read+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0bfa38d57d
Code: a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb b5 e8 a8 48 00 00 0f 1f 84 00 00 00 00 00 80 3d e1 af 21 00 00 74 17 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 5b c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec
RSP: 002b:00007ffce5767a48 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0bfa38d57d
RDX: 0000000000000004 RSI: 00007ffce5767a5c RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000016e2b905 R09: 7fffffffffffffff
R10: 3fffffffffffffff R11: 0000000000000246 R12: 00007ffce5767e70
R13: 0000000000000004 R14: 00007ffce5767a5c R15: 00007ffce5767af0
 </TASK>
