------------[ cut here ]------------
!rwb
WARNING: block/blk-wbt.c:785 at wbt_init_enable_default+0x18a/0x220 block/blk-wbt.c:785, CPU#0: syz.2.531/8549
Modules linked in:
CPU: 0 UID: 0 PID: 8549 Comm: syz.2.531 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:wbt_init_enable_default+0x18a/0x220 block/blk-wbt.c:785
Code: 1c 84 c0 0f 85 8d 00 00 00 41 21 2e eb 1f e8 8d 95 25 fd eb 18 e8 86 95 25 fd eb 0d e8 7f 95 25 fd 4c 89 ff e8 47 48 83 fd 90 <0f> 0b 90 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc
RSP: 0018:ffffc90003577a70 EFLAGS: 00010282
RAX: bc9fc1a12c23d000 RBX: 1ffff1100d773d84 RCX: 0000000000000046
RDX: 0000000000000006 RSI: ffffffff8dfc0ce0 RDI: ffffffff8c287de0
RBP: dffffc0000000000 R08: ffffffff9031b4f7 R09: 1ffffffff206369e
R10: dffffc0000000000 R11: fffffbfff206369f R12: ffff88806bb9ec20
R13: 0000000000000000 R14: ffff88802c236000 R15: ffff88806bb9ec00
FS:  00007f634e40e6c0(0000) GS:ffff88812525c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000008000 CR3: 000000003326a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 blk_register_queue+0x409/0x4e0 block/blk-sysfs.c:990
 __add_disk+0x677/0xd50 block/genhd.c:528
 add_disk_fwnode+0xfb/0x480 block/genhd.c:597
 add_disk include/linux/blkdev.h:794 [inline]
 loop_add+0x85e/0xb40 drivers/block/loop.c:2092
 loop_control_ioctl+0x12e/0x5a0 drivers/block/loop.c:2219
 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+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f634d59c819
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:00007f634e40e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f634d816090 RCX: 00007f634d59c819
RDX: ffffffffffffffb6 RSI: 0000000000004c80 RDI: 0000000000000003
RBP: 00007f634d632c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f634d816128 R14: 00007f634d816090 R15: 00007fffba7cc338
 </TASK>