sysfs: cannot create duplicate filename '/devices/virtual/bdi/43:0'
------------[ cut here ]------------
WARNING: CPU: 1 PID: 7984 at fs/sysfs/dir.c:30 sysfs_warn_dup.cold+0x17/0x26 fs/sysfs/dir.c:30
Kernel panic - not syncing: kernel: panic_on_warn set ...

CPU: 1 PID: 7984 Comm: syz-executor326 Not tainted 4.14.306-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 panic+0x21d/0x451 kernel/panic.c:247
 check_panic_on_warn.cold+0x19/0x35 kernel/panic.c:171
 __warn+0xdf/0x1e0 kernel/panic.c:603
 report_bug+0x208/0x250 lib/bug.c:183
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [inline]
 do_error_trap+0x195/0x2d0 arch/x86/kernel/traps.c:295
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:967
RIP: 0010:sysfs_warn_dup.cold+0x17/0x26 fs/sysfs/dir.c:30
RSP: 0018:ffff8880a247f180 EFLAGS: 00010286
RAX: 0000000000000043 RBX: ffff888095428b10 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff878bd360 RDI: ffffed101448fe26
RBP: ffff888095414200 R08: 0000000000000043 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880af1bf0e0
R13: ffff8880b19a8b40 R14: ffff888095428b18 R15: ffff888097b15498
 sysfs_create_dir_ns+0x16f/0x1d0 fs/sysfs/dir.c:59
 create_dir lib/kobject.c:71 [inline]
 kobject_add_internal+0x28b/0x930 lib/kobject.c:229
 kobject_add_varg lib/kobject.c:364 [inline]
 kobject_add+0x11f/0x180 lib/kobject.c:409
 device_add+0x33f/0x15c0 drivers/base/core.c:1885
 device_create_groups_vargs+0x1dc/0x250 drivers/base/core.c:2529
 device_create_vargs+0x3a/0x50 drivers/base/core.c:2569
 bdi_register_va.part.0+0x35/0x650 mm/backing-dev.c:880
 bdi_register_va mm/backing-dev.c:908 [inline]
 bdi_register+0x101/0x110 mm/backing-dev.c:905
 bdi_register_owner+0x59/0xf0 mm/backing-dev.c:915
 device_add_disk+0x5bb/0xdc0 block/genhd.c:678
 add_disk include/linux/genhd.h:396 [inline]
 nbd_dev_add+0x60e/0x800 drivers/block/nbd.c:1683
 nbd_genl_connect+0x36c/0x13e0 drivers/block/nbd.c:1775
 genl_family_rcv_msg+0x572/0xb20 net/netlink/genetlink.c:600
 genl_rcv_msg+0xaf/0x140 net/netlink/genetlink.c:625
 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2461
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:636
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x651/0xbc0 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0x100 net/socket.c:656
 ___sys_sendmsg+0x6c8/0x800 net/socket.c:2062
 __sys_sendmsg+0xa3/0x120 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0x27/0x40 net/socket.c:2103
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3
RIP: 0033:0x7f773fbc3b39
RSP: 002b:00007fff9da8d018 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f773fbc3b39
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000003
RBP: 00007f773fb875a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f773fb87630
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..