------------[ cut here ]------------
!rwb
WARNING: block/blk-wbt.c:784 at wbt_init_enable_default+0x148/0x1a0 block/blk-wbt.c:784, CPU#0: syz.4.434/8291
Modules linked in:
CPU: 0 UID: 0 PID: 8291 Comm: syz.4.434 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:wbt_init_enable_default+0x148/0x1a0 block/blk-wbt.c:784
Code: 41 5c 41 5d 41 5e 41 5f 5d e9 e4 1c 06 07 e8 5f f6 2d fd eb 18 e8 58 f6 2d fd eb 0d e8 51 f6 2d fd 4c 89 ff e8 a9 56 8a fd 90 <0f> 0b 90 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d e9 5d d9 79 fc
RSP: 0018:ffffc9001ea27a88 EFLAGS: 00010286
RAX: c4cec68afe3d7100 RBX: 1ffff1100f785784 RCX: 0000000000000046
RDX: 0000000000000006 RSI: ffffffff8dcd337e RDI: ffffffff8c078580
RBP: dffffc0000000000 R08: ffffffff8fefa777 R09: 1ffffffff1fdf4ee
R10: dffffc0000000000 R11: fffffbfff1fdf4ef R12: ffff88807bc2bc20
R13: 0000000000000000 R14: ffff88807c97a000 R15: ffff88807bc2bc00
FS:  00007f937c5d56c0(0000) GS:ffff8881256d7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe870f84cc0 CR3: 0000000041318000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 blk_register_queue+0x36a/0x3f0 block/blk-sysfs.c:942
 __add_disk+0x677/0xd50 block/genhd.c:528
 add_disk_fwnode+0xfb/0x480 block/genhd.c:597
 add_disk include/linux/blkdev.h:785 [inline]
 loop_add+0x85e/0xb40 drivers/block/loop.c:2093
 loop_control_ioctl+0x12e/0x5a0 drivers/block/loop.c:2220
 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+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f937e39bf79
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f937c5d5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f937e616180 RCX: 00007f937e39bf79
RDX: 00000000000fffff RSI: 0000000000004c80 RDI: 000000000000000a
RBP: 00007f937e4327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f937e616218 R14: 00007f937e616180 R15: 00007ffc8c130208
 </TASK>