syzbot

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!rwb
WARNING: block/blk-wbt.c:785 at wbt_init_enable_default+0x18a/0x220 block/blk-wbt.c:785, CPU#0: syz.1.1043/11623
Modules linked in:
CPU: 0 UID: 0 PID: 11623 Comm: syz.1.1043 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 3d b2 24 fd eb 18 e8 36 b2 24 fd eb 0d e8 2f b2 24 fd 4c 89 ff e8 87 e9 82 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:ffffc90005f6fa70 EFLAGS: 00010282
RAX: be226af79054cd00 RBX: 1ffff1100f7b2184 RCX: 0000000000000046
RDX: 0000000000000006 RSI: ffffffff8defbe6a RDI: ffffffff8c27d580
RBP: dffffc0000000000 R08: ffffffff9011dbb7 R09: 1ffffffff2023b76
R10: dffffc0000000000 R11: fffffbfff2023b77 R12: ffff88807bd90c20
R13: 0000000000000000 R14: ffff88807bb46000 R15: ffff88807bd90c00
FS:  00007f551ebbc6c0(0000) GS:ffff888125454000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000183030 CR3: 000000005b95a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 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+0x85e/0xb40 drivers/block/loop.c:2092
 loop_control_get_free drivers/block/loop.c:2208 [inline]
 loop_control_ioctl+0x2f8/0x5a0 drivers/block/loop.c:2223
 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+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f551f59c819
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:00007f551ebbc028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f551f816270 RCX: 00007f551f59c819
RDX: 0000000000000000 RSI: 0000000000004c82 RDI: 0000000000000005
RBP: 00007f551f632c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f551f816308 R14: 00007f551f816270 R15: 00007ffd77c576d8
 </TASK>