------------[ cut here ]------------ !rwb WARNING: block/blk-wbt.c:785 at wbt_init_enable_default+0x18a/0x220 block/blk-wbt.c:785, CPU#0: syz.7.730/13150 Modules linked in: CPU: 0 UID: 0 PID: 13150 Comm: syz.7.730 Not tainted syzkaller #0 PREEMPT_{RT,(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 6d a0 33 fd eb 18 e8 66 a0 33 fd eb 0d e8 5f a0 33 fd 4c 89 ff e8 77 e1 8d fd 90 <0f> 0b 90 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d e9 10 11 97 06 RSP: 0018:ffffc90003f8fa70 EFLAGS: 00010282 RAX: 4caa6748ba8c9600 RBX: 1ffff1100783a304 RCX: 0000000000000046 RDX: 0000000000000006 RSI: ffffffff8d565a2d RDI: ffffffff8ba67a00 RBP: dffffc0000000000 R08: ffffffff8f6a73b7 R09: 1ffffffff1ed4e76 R10: dffffc0000000000 R11: fffffbfff1ed4e77 R12: ffff88803c1d1820 R13: 0000000000000000 R14: ffff888036945000 R15: ffff88803c1d1800 FS: 00007fa8630ac6c0(0000) GS:ffff888126332000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555560ed39e8 CR3: 000000007526c000 CR4: 00000000003526f0 Call Trace: blk_register_queue+0x382/0x430 block/blk-sysfs.c:949 __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+0x86e/0xb50 drivers/block/loop.c:2092 loop_control_ioctl+0x12e/0x5b0 drivers/block/loop.c:2219 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa864e9c819 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:00007fa8630ac028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa865116180 RCX: 00007fa864e9c819 RDX: 0000000000010003 RSI: 0000000000004c80 RDI: 0000000000000009 RBP: 00007fa864f32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa865116218 R14: 00007fa865116180 R15: 00007ffe323b0898