INFO: task syz-executor:32130 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:18856 pid:32130 tgid:32130 ppid:1      task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 wb_wait_for_completion+0x15f/0x260
 __writeback_inodes_sb_nr+0x1f6/0x250
 sync_filesystem+0xa3/0x230
 generic_shutdown_super+0x6f/0x2c0
 bch2_kill_sb+0x41/0x50
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f694078ff17
RSP: 002b:00007ffc37bcee38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f6940811c05 RCX: 00007f694078ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc37bceef0
RBP: 00007ffc37bceef0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc37bcff80
R13: 00007f6940811c05 R14: 000000000008b991 R15: 00007ffc37bcffc0
 </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: 18662 Comm: dhcpcd-run-hook 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:__rcu_read_lock+0x2a/0x60
Code: f3 0f 1e fa 53 65 48 8b 1c 25 08 50 a0 92 48 81 c3 44 04 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 <84> c0 75 18 ff 03 8b 03 3d 00 00 00 40 7d 07 5b c3 cc cc cc cc cc
RSP: 0018:ffffc90007176e28 EFLAGS: 00000a03
RAX: 0000000000000000 RBX: ffff8881052f2104 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: ffffffff820c0531 RDI: ffffc90007176f08
RBP: dffffc0000000000 R08: ffffc90007176fd0 R09: 0000000000000006
R10: ffffc90007176f58 R11: ffffffff81ac3810 R12: 1ffff92000e2ede1
R13: ffffc90007176f40 R14: ffffc90007176f08 R15: ffffc900071773a0
FS:  00007eff6476e380(0000) GS:ffff8880b861b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056167611af18 CR3: 00000001251c6000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 unwind_next_frame+0x9e/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 ptlock_alloc+0x20/0x70
 pte_alloc_one+0x7d/0x170
 __pte_alloc+0x25/0x1a0
 copy_pmd_range+0x6a91/0x71d0
 copy_page_range+0xc14/0x1270
 dup_mmap+0xf57/0x1ac0
 copy_mm+0x13c/0x4b0
 copy_process+0x1706/0x3c00
 kernel_clone+0x21e/0x840
 __x64_sys_clone+0x18b/0x1e0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7eff648a8a12
Code: 41 5d 41 5e 41 5f c3 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 10 48 8b 15 e7 43 0f 00 f7 d8 64 89 02 48 83
RSP: 002b:00007fffd2dbf498 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000561676112901 RCX: 00007eff648a8a12
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000561676113b70 R08: 0000000000000000 R09: ffffffffff000000
R10: 00007eff6476e650 R11: 0000000000000246 R12: 0000561676116aa0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
