INFO: task syz.0.484:8980 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.484       state:D stack:24736 pid:8980  tgid:8979  ppid:8825   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x61e/0x920
 down_read+0x99/0x2e0
 super_lock+0x2d6/0x3d0
 __iterate_supers+0x126/0x290
 __ia32_sys_sync+0xa0/0x120
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0971f9c799
RSP: 002b:00007f0972dee028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f0972215fa0 RCX: 00007f0971f9c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f0972215fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0972216038 R14: 00007f0972215fa0 R15: 00007ffd5ed20258
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/35:
 #0: ffffffff8e75e520 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5632:
 #0: ffff8881140090a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
3 locks held by kworker/u8:2/5677:
 #0: ffff88816ab96148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffff888121024588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
 #2: ffffffff8e75e520 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x23c0
2 locks held by sshd/5748:
5 locks held by syz-executor/5761:
3 locks held by syz-executor/7419:
2 locks held by syz-executor/8561:
1 lock held by syz.0.484/8980:
 #0: ffff8881af8120e0 (&type->s_umount_key#74){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.8.542/9509:
 #0: ffff8881af8120e0 (&type->s_umount_key#74){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.9.956/12212:
 #0: ffff8881af8120e0 (&type->s_umount_key#74){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.8.990/12454:
 #0: ffff8881af8120e0 (&type->s_umount_key#74){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
2 locks held by syz.3.996/12511:
3 locks held by syz-executor/12531:

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

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+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: 12511 Comm: syz.3.996 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:__sanitizer_cov_trace_pc+0x36/0x70
Code: 18 5f 56 11 65 8b 15 39 5f 56 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 a4 16 00 00 00 74 2c 8b 91 80 16 00 00 <83> fa 02 75 21 48 8b 91 88 16 00 00 48 8b 32 48 8d 7e 01 8b 89 84
RSP: 0018:ffffc9000954f310 EFLAGS: 00000246
RAX: ffffffff823c322c RBX: ffffffff823c31ea RCX: ffff88810e491d40
RDX: 0000000000000000 RSI: ffffffff8c27be60 RDI: ffffffff8c27be20
RBP: 0000000000000001 R08: ffffffff823c31ea R09: ffffffff8e75e5e0
R10: dffffc0000000000 R11: fffff940001d4f61 R12: dffffc0000000000
R13: dffffc0000000000 R14: 000000000003a9ec R15: ffff88814fef30e0
FS:  0000000000000000(0000) GS:ffff8882a9460000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005614248d6e38 CR3: 000000000e54c000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 pfn_valid+0xfc/0x480
 page_table_check_clear+0x21/0x5f0
 unmap_page_range+0x33b3/0x48f0
 unmap_vmas+0x48f/0x6a0
 exit_mmap+0x280/0xa10
 __mmput+0x118/0x430
 exit_mm+0x168/0x220
 do_exit+0x6a2/0x23c0
 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+0x32d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9f4955cfce
Code: Unable to access opcode bytes at 0x7f9f4955cfa4.
RSP: 002b:00007f9f4a4a2da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: 0000000000f43000 RBX: 00007f9f4a4a36c0 RCX: 00007f9f4955cfce
RDX: 0000000001000000 RSI: 00007f9f3f200000 RDI: 0000000000000009
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009
R13: 00007f9f4a4a2ee0 R14: 00007f9f4a4a2ea0 R15: 00007f9f3f200000
 </TASK>
