INFO: task syz.4.176:7257 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.176       state:D stack:13768 pid:7257  tgid:7256  ppid:6257   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 __closure_sync+0x163/0x220
 bch2_read_iter+0x1038/0x1440
 do_iter_readv_writev+0x623/0x8c0
 vfs_readv+0x253/0x850
 __se_sys_preadv2+0x179/0x290
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff71bf8ec29
RSP: 002b:00007ff71cda7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000147
RAX: ffffffffffffffda RBX: 00007ff71c1d5fa0 RCX: 00007ff71bf8ec29
RDX: 100000000000000d RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007ff71c011e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff71c1d6038 R14: 00007ff71c1d5fa0 R15: 00007ffe60e340c8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e33d320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5679:
 #0: ffff88810f7f50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000290e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
1 lock held by udevd/9233:
1 lock held by udevd/9234:
2 locks held by syz.1.402/9275:
7 locks held by syz.9.403/9277:
1 lock held by udevd/9278:

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

NMI backtrace for cpu 0
CPU: 0 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+0xf60/0xfa0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 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: 9277 Comm: syz.9.403 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+0x5c8/0xd20
Code: 8b 3c 24 e9 56 ff ff ff 83 bf 14 0b 00 00 00 41 0f 94 c4 45 00 e4 41 80 c4 03 44 3b bf 28 0b 00 00 0f 8c fc fe ff ff 44 89 e0 <41> 38 c5 76 1a e8 9e 87 2c 03 48 8b 3c 24 85 c0 74 0d 83 3d 73 81
RSP: 0018:ffffc90002fb6f08 EFLAGS: 00000046
RAX: 0000000000000004 RBX: 0000000000000002 RCX: 0000000000000002
RDX: 0000000000000004 RSI: 0000000000000005 RDI: ffff888109169d00
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81742d25
R10: ffffc90002fb7158 R11: ffffffff81acd510 R12: 0000000000000004
R13: 0000000000000001 R14: ffff88810916a880 R15: ffff88810916a8a0
FS:  00007f0827aeb6c0(0000) GS:ffff8881a39fc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f081d7ff000 CR3: 000000011bb80000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x120/0x360
 unwind_next_frame+0xc2/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 save_stack+0xf5/0x1f0
 __set_page_owner+0x8d/0x4a0
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x2365/0x2440
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 folio_alloc_mpol_noprof+0x39/0x70
 shmem_alloc_and_add_folio+0x447/0xf60
 shmem_get_folio_gfp+0x59d/0x1660
 shmem_write_begin+0xf7/0x2b0
 generic_perform_write+0x2c5/0x900
 shmem_file_write_iter+0xf8/0x120
 vfs_write+0x5c9/0xb30
 ksys_write+0x145/0x250
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0826b8d6df
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007f0827aeadf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f0826b8d6df
RDX: 0000000001000000 RSI: 00007f081c800000 RDI: 0000000000000006
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000005a0a
R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000006
R13: 00007f0827aeaef0 R14: 00007f0827aeaeb0 R15: 00007f081c800000
 </TASK>
