INFO: task syz.7.489:8717 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.489       state:D stack:24296 pid:8717  tgid:8716  ppid:8053   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 sync_bdevs+0x1ac/0x340
 ksys_sync+0xb9/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f473a98ebe9
RSP: 002b:00007f473b802038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f473abb5fa0 RCX: 00007f473a98ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f473abb5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f473abb6038 R14: 00007f473abb5fa0 R15: 00007ffc9935a738
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 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+0x3fc/0x770
 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: 13098 Comm: syz.4.1204 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:its_return_thunk+0x0/0x10
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 6b 13 b7 f5 cc
RSP: 0018:ffffc90006b07428 EFLAGS: 00000293
RAX: ffffffff822e424d RBX: 0000000000012a45 RCX: ffff88801fc9b980
RDX: 0000000000000000 RSI: 0000000000002a46 RDI: 0000000000000000
RBP: ffff88801b0d3590 R08: ffff88801b0d35df R09: 1ffff1100361a6bb
R10: dffffc0000000000 R11: ffffed100361a6bc R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000012a46 R15: ffff88801b0d35d8
FS:  00007f4f1cf846c0(0000) GS:ffff8880b861b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4f131bd000 CR3: 00000000218e2000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 page_table_check_clear+0x3ad/0x700
 unmap_page_range+0x340f/0x4370
 unmap_vmas+0x399/0x580
 vms_clear_ptes+0x35c/0x540
 vms_complete_munmap_vmas+0x206/0x8a0
 do_vmi_align_munmap+0x358/0x420
 do_vmi_munmap+0x253/0x2e0
 __vm_munmap+0x23b/0x3d0
 __x64_sys_munmap+0x60/0x70
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4f1c18ec77
Code: 00 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4f1cf83e18 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 00000000013bd7ef RCX: 00007f4f1c18ec77
RDX: 0000000000000000 RSI: 0000000008400000 RDI: 00007f4f11e00000
RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000054ff
R10: 00000000000003c8 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f4f1cf83ef0 R14: 00007f4f1cf83eb0 R15: 00007f4f11e00000
 </TASK>
