INFO: task syz.2.16582:11671 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.16582     state:D stack:27112 pid:11671 tgid:11659 ppid:5643   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: 0033:0x7f249a59cdd9
RSP: 002b:00007f249b374028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f249a816090 RCX: 00007f249a59cdd9
RDX: 0000000000000000 RSI: 00002000000001c0 RDI: 0000000000000008
RBP: 00007f249a632d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f249a816128 R14: 00007f249a816090 R15: 00007ffcce63f608
 </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 kworker/u10:3/1109:
 #0: ffff8881000ac940 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90007477c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
2 locks held by getty/5438:
 #0: ffff8881153830a0 (&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.0.14753/7270:
 #0: ffffffff8fe3f8c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670
3 locks held by syz-executor/7881:
2 locks held by syz.2.16582/11671:
 #0: ffffffff8fe3f8c8 (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.1.16762/12095:
 #0: ffffffff8fe3f8c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670
1 lock held by syz.4.18543/16334:
 #0: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
1 lock held by modprobe/16337:

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

NMI backtrace for cpu 0
CPU: 0 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 7881 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 e9 c0 26 37 0a cc 89 f6 31 d2 e9 66 54 7a 03 66 0f 1f 44 00
RSP: 0018:ffffc90000a086d0 EFLAGS: 00000046
RAX: 0000000000000110 RBX: ffff88823c623e40 RCX: 0000000000000838
RDX: 0000000000000000 RSI: 0000000000000110 RDI: 0000000000000838
RBP: ffffc90000a08798 R08: ffffffff81b2dfc5 R09: ffffffff9a493588
R10: 0000000000000003 R11: ffffffff817446c0 R12: 0000000000000110
R13: dffffc0000000000 R14: 000000001000192a R15: 0000000000000020
FS:  000055558131a500(0000) GS:ffff8882a9287000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3af1a69440 CR3: 000000000e74a000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 lapic_next_event+0x11/0x20
 clockevents_program_event+0x385/0x630
 __hrtimer_rearm_deferred+0x270/0x450
 irqentry_exit+0x6a0/0x730
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:unwind_next_frame+0x50e/0x2550
Code: c1 e8 3f 48 01 c8 48 83 e0 fe 4c 8d 3c 45 00 00 00 00 49 01 ef 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 <84> c0 75 27 49 63 07 4c 01 f8 49 8d 4f 04 4c 39 e0 48 0f 46 e9 49
RSP: 0018:ffffc90000a088f8 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: ffffffff904a13c8 RCX: dffffc0000000000
RDX: ffffffff904a13b8 RSI: ffffffff90c63bba RDI: ffffffff8c28ad80
RBP: ffffffff904a13b8 R08: 0000000000000005 R09: ffffffff8e95cd60
R10: ffffc90000a08a18 R11: ffffffff81b0e910 R12: ffffffff818a8233
R13: ffffffff904a13b8 R14: ffffc90000a089c8 R15: ffffffff904a13c0
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5c/0x80
 slab_free_after_rcu_debug+0x12a/0x220
 rcu_core+0x7cd/0x1070
 handle_softirqs+0x22a/0x840
 __irq_exit_rcu+0xca/0x220
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:finish_task_switch+0x427/0xbe0
Code: 41 c7 84 24 e0 0d 00 00 00 00 00 00 0f 1f 44 00 00 49 83 c4 48 4c 89 e7 e8 d6 59 17 0a e8 11 f6 38 00 fb 49 8d bd a8 16 00 00 <48> 89 f8 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 7b 03 00 00 41 80
RSP: 0018:ffffc9000808f1d0 EFLAGS: 00000206
RAX: 0000000000501563 RBX: 1ffff110478c7784 RCX: 0000000080000001
RDX: 0000000000000006 RSI: ffffffff8dfaaad9 RDI: ffff8881729251a8
RBP: ffffc9000808f230 R08: ffffffff9030dbf7 R09: 1ffffffff2061b7e
R10: dffffc0000000000 R11: fffffbfff2061b7f R12: ffff88823c63ae88
R13: ffff888172923b00 R14: ffff88810b741d80 R15: dffffc0000000000
 __schedule+0x17bc/0x5680
 preempt_schedule_irq+0x4d/0xa0
 irqentry_exit+0x14f/0x730
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__sanitizer_cov_trace_pc+0x17/0x70
Code: cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d 88 d0 73 11 65 8b 15 a9 d0 73 11 <81> e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 cc 16 00 00
RSP: 0000:ffffc9000808f580 EFLAGS: 00000202
RAX: ffffffff8ba21102 RBX: 0000000000000001 RCX: ffff888172923b00
RDX: 0000000080000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff88818cd2aa80 R08: ffff888172923b00 R09: 0000000000000005
R10: 0000000000000004 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff8881a0c62a00 R14: 0000000000000001 R15: ffffffffffffffff
 mas_next_slot+0x9b2/0xd10
 mas_find+0xb0e/0xd30
 free_pgtables+0x712/0xb70
 exit_mmap+0x490/0x9e0
 __mmput+0x118/0x430
 exit_mm+0x18e/0x250
 do_exit+0x6a2/0x22c0
 do_group_exit+0x21b/0x2d0
 get_signal+0x1284/0x1330
 arch_do_signal_or_restart+0xbc/0x830
 exit_to_user_mode_loop+0x86/0x480
 do_syscall_64+0x33e/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f039475d60e
Code: Unable to access opcode bytes at 0x7f039475d5e4.
RSP: 002b:00007ffcb2ce1288 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 000055558131a500 RCX: 00007f039475d60e
RDX: 00007ffcb2ce12e0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffcb2ce134c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000001388
R13: 00000000000927c0 R14: 00000000000e4d07 R15: 00007ffcb2ce13a0
 </TASK>
