INFO: task syz-executor:5846 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:21832 pid:5846  tgid:5846  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: 0033:0x7f41cd78ff17
RSP: 002b:00007ffdf85f21b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f41cd811c05 RCX: 00007f41cd78ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdf85f2270
RBP: 00007ffdf85f2270 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffdf85f3300
R13: 00007f41cd811c05 R14: 000000000000f8f8 R15: 00007ffdf85f3340
 </TASK>

Showing all locks held in the system:
2 locks held by kworker/u8:0/12:
 #0: ffff88804b039f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffffc900000f7bc0 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by kworker/u9:4/634:
 #0: ffff88810070f948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003aafbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
2 locks held by getty/5672:
 #0: ffff8881070100a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
1 lock held by syz-executor/5846:
 #0: ffff888020c160e0 (&type->s_umount_key#65){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
3 locks held by syz.1.825/9109:
3 locks held by syz.3.822/9111:

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

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: 9111 Comm: syz.3.822 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:__lock_acquire+0xa4f/0xd20
Code: e5 ff 90 0f 0b 90 90 90 31 c0 48 8b 3c 24 48 83 78 40 00 0f 84 8c 02 00 00 41 8b 46 20 25 ff 1f 00 00 48 0f a3 05 21 08 0b 12 <73> 10 48 69 c0 c8 00 00 00 48 8d 80 10 73 49 93 eb 40 83 3d 88 97
RSP: 0018:ffffc900045be6d0 EFLAGS: 00000003
RAX: 0000000000000007 RBX: 0000000000000002 RCX: 000000008d81afaa
RDX: 00000000d6805b46 RSI: 000000007f360bd7 RDI: ffff88801cb55640
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff822bd229
R10: dffffc0000000000 R11: ffffed10036de041 R12: 000000003973fa47
R13: ffff88801cb56130 R14: ffff88801cb56180 R15: 531c899b8d81afaa
FS:  00007f11f456f6c0(0000) GS:ffff8880b8615000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f11f454ed58 CR3: 000000002b0dc000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x120/0x360
 percpu_ref_get_many+0x35/0x140
 charge_memcg+0xcb/0x180
 __mem_cgroup_charge+0x25/0x80
 shmem_alloc_and_add_folio+0x7c1/0xf60
 shmem_get_folio_gfp+0x59d/0x1660
 shmem_write_begin+0xf7/0x2b0
 generic_perform_write+0x2c5/0x900
 shmem_file_write_iter+0xf8/0x120
 __kernel_write_iter+0x428/0x910
 dump_user_range+0x8a0/0xc90
 elf_core_dump+0x337b/0x3990
 coredump_write+0x1169/0x1900
 vfs_coredump+0x1daa/0x2a50
 get_signal+0x1109/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 irqentry_exit_to_user_mode+0x81/0x120
 exc_page_fault+0x9f/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7f11f378ebf1
Code: 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 48 3d 01 f0 ff ff 73 01 <c3> 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:fffffffffffffde0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f11f39c5fa0 RCX: 00007f11f378ebe9
RDX: 0000000000000000 RSI: fffffffffffffde0 RDI: 0000000000800091
RBP: 00007f11f3811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f11f39c6038 R14: 00007f11f39c5fa0 R15: 00007ffe7ffc9508
 </TASK>
