R13: 00007ffd3149dc4f R14: 00007f6a4c717300 R15: 0000000000022000
kobject_add_internal failed for 2427:0 with -EEXIST, don't try to register things with the same name in the same directory.
------------[ cut here ]------------
WARNING: CPU: 1 PID: 12421 at block/genhd.c:719 __device_add_disk.cold+0x69/0x188 block/genhd.c:719
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 12421 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 panic+0x26a/0x50e kernel/panic.c:186
 __warn.cold+0x20/0x5a kernel/panic.c:541
 report_bug+0x262/0x2b0 lib/bug.c:183
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x1d7/0x310 arch/x86/kernel/traps.c:296
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038
RIP: 0010:__device_add_disk.cold+0x69/0x188 block/genhd.c:719
Code: 02 84 c0 74 08 3c 03 0f 8e a8 00 00 00 44 8b a5 f0 05 00 00 e9 67 ad 6a fb e8 05 45 66 f9 48 c7 c7 60 75 b2 88 e8 64 76 f7 ff <0f> 0b e9 8f b9 6a fb e8 ed 44 66 f9 48 c7 c7 60 75 b2 88 e8 4c 76
RSP: 0018:ffff88808d907488 EFLAGS: 00010282
RAX: 0000000000000024 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000040000 RSI: ffffffff814dff01 RDI: ffffed1011b20e83
RBP: ffff88808f97ad00 R08: 0000000000000024 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff88808f97ad90
R13: ffff88808f97b390 R14: 00000000ffffffef R15: ffff88808f97ad04
 add_disk include/linux/genhd.h:409 [inline]
 nbd_dev_add+0x6a9/0x890 drivers/block/nbd.c:1692
 nbd_genl_connect+0x488/0x1630 drivers/block/nbd.c:1784
 genl_family_rcv_msg+0x642/0xc40 net/netlink/genetlink.c:602
 genl_rcv_msg+0xbf/0x160 net/netlink/genetlink.c:627
 netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2463
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:638
 netlink_unicast_kernel net/netlink/af_netlink.c:1325 [inline]
 netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1351
 netlink_sendmsg+0x6c3/0xc50 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xc3/0x120 net/socket.c:661
 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2227
 __sys_sendmsg net/socket.c:2265 [inline]
 __do_sys_sendmsg net/socket.c:2274 [inline]
 __se_sys_sendmsg net/socket.c:2272 [inline]
 __x64_sys_sendmsg+0x132/0x220 net/socket.c:2272
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f6a4e1a4639
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6a4c717168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f6a4e2c4f80 RCX: 00007f6a4e1a4639
RDX: 0000000000000000 RSI: 0000000020000400 RDI: 0000000000000005
RBP: 00007f6a4e1ffae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd3149dc4f R14: 00007f6a4c717300 R15: 0000000000022000
Kernel Offset: disabled
Rebooting in 86400 seconds..