------------[ cut here ]------------ WARNING: block/blk-wbt.c:741 at wbt_init_enable_default+0x4e/0x60 block/blk-wbt.c:741, CPU#2: syz.1.18/6107 Modules linked in: CPU: 2 UID: 0 PID: 6107 Comm: syz.1.18 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:wbt_init_enable_default+0x4e/0x60 block/blk-wbt.c:741 Code: 07 5b 5d e9 e4 8c 22 fd e8 df 8c 22 fd 48 89 ef e8 77 fa ff ff 31 ff 89 c3 89 c6 e8 6c 87 22 fd 85 db 74 dd e8 c3 8c 22 fd 90 <0f> 0b 90 eb d2 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 RSP: 0018:ffffc90006d4f1a8 EFLAGS: 00010283 RAX: 000000000001782a RBX: 00000000fffffff4 RCX: ffffc90025fa9000 RDX: 0000000000080000 RSI: ffffffff849bcbdd RDI: 0000000000000005 RBP: ffff888028aca000 R08: 0000000000000005 R09: 0000000000000000 R10: 00000000fffffff4 R11: ffff88804d1d54b0 R12: ffff888044601c98 R13: ffff888028aca390 R14: ffff888044601ca8 R15: ffff888028aca090 FS: 0000000000000000(0000) GS:ffff8880978fc000(0063) knlGS:00000000f546cb40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f4402f80 CR3: 0000000000dde000 CR4: 0000000000352ef0 Call Trace: blk_register_queue+0x39e/0x4e0 block/blk-sysfs.c:935 __add_disk+0x74a/0xf00 block/genhd.c:528 add_disk_fwnode+0x13f/0x5d0 block/genhd.c:597 add_disk include/linux/blkdev.h:785 [inline] nbd_dev_add+0x783/0xbb0 drivers/block/nbd.c:1984 nbd_genl_connect+0x8b0/0x1c60 drivers/block/nbd.c:2125 genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x158/0x420 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+0x5aa/0x870 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646 __sys_sendmsg+0x16d/0x220 net/socket.c:2678 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe8/0x680 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf709d579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f546c55c EFLAGS: 00000296 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 0000000080000240 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi