"mq-deadline" elevator initialization, failed -12, falling back to "none"
------------[ cut here ]------------
!rwb
WARNING: block/blk-wbt.c:784 at wbt_init_enable_default+0x148/0x1a0 block/blk-wbt.c:784, CPU#0: syz.8.686/8813
Modules linked in:
CPU: 0 UID: 0 PID: 8813 Comm: syz.8.686 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+0x148/0x1a0 block/blk-wbt.c:784
Code: 41 5c 41 5d 41 5e 41 5f 5d e9 64 69 0e 07 e8 1f b8 26 fd eb 18 e8 18 b8 26 fd eb 0d e8 11 b8 26 fd 4c 89 ff e8 29 a9 84 fd 90 <0f> 0b 90 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d e9 fd 70 71 fc
RSP: 0018:ffffc90004f9ee48 EFLAGS: 00010292
RAX: 1fd37ba4cae60b00 RBX: 1ffff1100a878404 RCX: 0000000000000046
RDX: 0000000000000006 RSI: ffffffff8deed5c3 RDI: ffffffff8c279800
RBP: dffffc0000000000 R08: ffffffff90114db7 R09: 1ffffffff20229b6
R10: dffffc0000000000 R11: fffffbfff20229b7 R12: ffff8880543c2020
R13: 0000000000000000 R14: ffff88803670b000 R15: ffff8880543c2000
FS:  00007fc51d8a06c0(0000) GS:ffff88812546f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000b7030 CR3: 000000007d876000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 blk_register_queue+0x36a/0x3f0 block/blk-sysfs.c:942
 __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]
 nbd_dev_add+0x72c/0xb50 drivers/block/nbd.c:1984
 nbd_genl_connect+0x962/0x1cf0 drivers/block/nbd.c:2125
 genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa68/0xad0 net/socket.c:2592
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2683 [inline]
 __se_sys_sendmsg net/socket.c:2681 [inline]
 __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681
 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: 0033:0x7fc51c99bf79
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:00007fc51d8a0028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc51cc15fa0 RCX: 00007fc51c99bf79
RDX: 0000000000000004 RSI: 0000200000000240 RDI: 0000000000000003
RBP: 00007fc51ca327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc51cc16038 R14: 00007fc51cc15fa0 R15: 00007fff12769568
 </TASK>