"mq-deadline" elevator initialization, failed -12, falling back to "none"
------------[ cut here ]------------
!rwb
WARNING: block/blk-wbt.c:785 at wbt_init_enable_default+0x164/0x1c0 block/blk-wbt.c:785, CPU#1: syz.6.662/9369
Modules linked in:
CPU: 1 UID: 0 PID: 9369 Comm: syz.6.662 Not tainted syzkaller #0 PREEMPT(full) 
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: 4c 21 fd 5b 5d 41 5c 41 5d 41 5e e9 91 b1 28 fc 4c 89 f7 e8 ee e6 8c fd eb 83 4c 89 f7 e8 e4 e6 8c fd eb d0 e8 6d 4c 21 fd 90 <0f> 0b 90 e9 e9 fe ff ff e8 5f 4c 21 fd 90 0f 0b 90 48 b8 00 00 00
RSP: 0018:ffffc900050ef180 EFLAGS: 00010283
RAX: 000000000001ed73 RBX: ffff8880236e1000 RCX: ffffc9001ed56000
RDX: 0000000000080000 RSI: ffffffff84e78f93 RDI: ffffffff8c1b1e20
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88802b451310
R13: ffff8880342a002c R14: ffff8880236e1390 R15: ffff88802b451320
FS:  00007fb8f43886c0(0000) GS:ffff888124439000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e91bff8 CR3: 0000000084784000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 blk_register_queue+0x42c/0x590 block/blk-sysfs.c:949
 __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]
 nbd_dev_add+0x77a/0xb10 drivers/block/nbd.c:1984
 nbd_genl_connect+0xb8d/0x1a40 drivers/block/nbd.c:2125
 genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0x9e1/0xb70 net/socket.c:2592
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2646
 __sys_sendmsg+0x170/0x220 net/socket.c:2678
 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: 0033:0x7fb8f359c819
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:00007fb8f4388028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fb8f3816090 RCX: 00007fb8f359c819
RDX: 0000000000000004 RSI: 0000200000000240 RDI: 0000000000000005
RBP: 00007fb8f3632c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb8f3816128 R14: 00007fb8f3816090 R15: 00007ffcaf35eed8
 </TASK>