------------[ cut here ]------------
WARNING: block/blk-wbt.c:741 at wbt_init_enable_default+0x4e/0x60 block/blk-wbt.c:741, CPU#0: syz.0.176/6937
Modules linked in:
CPU: 0 UID: 0 PID: 6937 Comm: syz.0.176 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:wbt_init_enable_default+0x4e/0x60 block/blk-wbt.c:741
Code: ff 89 c6 e8 b4 e3 40 fd 85 db 75 18 e8 6b df 40 fd 5b e9 c0 2a 90 fc cc e8 5f df 40 fd 5b e9 b4 2a 90 fc cc e8 53 df 40 fd 90 <0f> 0b 90 5b e9 a4 2a 90 fc cc 0f 1f 84 00 00 00 00 00 90 90 90 90
RSP: 0018:ffffc90003117ab8 EFLAGS: 00010293
RAX: ffffffff8480165d RBX: 00000000fffffff4 RCX: ffff888025e9bd00
RDX: 0000000000000000 RSI: 00000000fffffff4 RDI: 0000000000000000
RBP: 1ffff1100f6c5012 R08: ffffffff8f822177 R09: 1ffffffff1f0442e
R10: dffffc0000000000 R11: fffffbfff1f0442f R12: 0000000000000000
R13: 1ffff1100515a98a R14: ffff88807b628000 R15: ffff888028ad4c40
FS:  00007f0ed9b706c0(0000) GS:ffff888125e21000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdfb63b9358 CR3: 000000005fb29000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 blk_register_queue+0x36a/0x3f0 block/blk-sysfs.c:935
 __add_disk+0x677/0xd50 block/genhd.c:528
 add_disk_fwnode+0xfc/0x480 block/genhd.c:597
 add_disk include/linux/blkdev.h:785 [inline]
 loop_add+0x7f0/0xad0 drivers/block/loop.c:2093
 loop_control_get_free drivers/block/loop.c:2209 [inline]
 loop_control_ioctl+0x2f2/0x5a0 drivers/block/loop.c:2224
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0ed8d8f749
Code: ff ff c3 66 2e 0f 1f 84 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
RSP: 002b:00007f0ed9b70038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f0ed8fe6180 RCX: 00007f0ed8d8f749
RDX: 0000000000000000 RSI: 0000000000004c82 RDI: 0000000000000007
RBP: 00007f0ed8e13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0ed8fe6218 R14: 00007f0ed8fe6180 R15: 00007ffd159f2718
 </TASK>