------------[ cut here ]------------ !rwb WARNING: block/blk-wbt.c:785 at wbt_init_enable_default+0x164/0x1c0 block/blk-wbt.c:785, CPU#0: syz.1.962/11280 Modules linked in: CPU: 0 UID: 0 PID: 11280 Comm: syz.1.962 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:wbt_init_enable_default+0x164/0x1c0 block/blk-wbt.c:785 Code: 0b 23 fd 5b 5d 41 5c 41 5d 41 5e c3 cc cc cc cc 4c 89 f7 e8 1e 65 8e fd eb 83 4c 89 f7 e8 14 65 8e fd eb d0 e8 dd 0a 23 fd 90 <0f> 0b 90 e9 e9 fe ff ff e8 cf 0a 23 fd 90 0f 0b 90 48 b8 00 00 00 RSP: 0018:ffffc9000522fb50 EFLAGS: 00010283 RAX: 0000000000012e54 RBX: ffff888026ca2000 RCX: ffffc9000e999000 RDX: 0000000000080000 RSI: ffffffff84e4ef03 RDI: ffffffff8c1aeb20 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: ffffffff81000130 R12: ffff888027b9df50 R13: ffff8880319c002c R14: ffff888026ca2390 R15: ffff888027b9df60 FS: 00007f78caa916c0(0000) GS:ffff888124351000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4614f2a286 CR3: 0000000052d16000 CR4: 00000000003526f0 Call Trace: blk_register_queue+0x42c/0x590 block/blk-sysfs.c:943 __add_disk+0x73f/0xe40 block/genhd.c:528 add_disk_fwnode+0x118/0x5c0 block/genhd.c:597 add_disk include/linux/blkdev.h:785 [inline] loop_add+0x90b/0xb60 drivers/block/loop.c:2093 loop_control_ioctl+0xae/0x620 drivers/block/loop.c:2220 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f78c9b9c629 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:00007f78caa91028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f78c9e15fa0 RCX: 00007f78c9b9c629 RDX: fffffffffffffffd RSI: 0000000000004c80 RDI: 0000000000000003 RBP: 00007f78c9c32b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f78c9e16038 R14: 00007f78c9e15fa0 R15: 00007ffc2fc20528