------------[ cut here ]------------
!sock_allow_reclassification(sk)
WARNING: drivers/block/nbd.c:1249 at nbd_reclassify_socket drivers/block/nbd.c:1249 [inline], CPU#0: syz.4.34/6044
WARNING: drivers/block/nbd.c:1249 at nbd_add_socket+0xf35/0x12c0 drivers/block/nbd.c:1293, CPU#0: syz.4.34/6044
Modules linked in:
CPU: 0 UID: 0 PID: 6044 Comm: syz.4.34 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:nbd_reclassify_socket drivers/block/nbd.c:1249 [inline]
RIP: 0010:nbd_add_socket+0xf35/0x12c0 drivers/block/nbd.c:1293
Code: f7 e8 ef 1d 20 fc bf e0 01 00 00 49 03 3e 48 c7 c6 00 29 55 8c e8 5b 18 19 fb b8 f0 ff ff ff e9 b2 fd ff ff e8 4c ff b2 fb 90 <0f> 0b 90 e9 16 f8 ff ff e8 de a1 97 05 44 89 e9 80 e1 07 fe c1 38
RSP: 0018:ffffc9000374f160 EFLAGS: 00010293
RAX: ffffffff861321f4 RBX: 1ffff1100633ca59 RCX: ffff88802f6cbe00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000374f250 R08: ffff8880203399df R09: 1ffff1100406733b
R10: dffffc0000000000 R11: ffffed100406733c R12: ffff8880319e5100
R13: 1ffff920006e9e38 R14: dffffc0000000000 R15: 0000000000000001
FS:  00007fb559fdd6c0(0000) GS:ffff88812526a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 000000007a3b4000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 nbd_genl_connect+0x133d/0x1c10 drivers/block/nbd.c:2254
 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec net/socket.c:775 [inline]
 __sock_sendmsg net/socket.c:790 [inline]
 ____sys_sendmsg+0x9b9/0xa20 net/socket.c:2684
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
 __sys_sendmsg net/socket.c:2770 [inline]
 __do_sys_sendmsg net/socket.c:2775 [inline]
 __se_sys_sendmsg net/socket.c:2773 [inline]
 __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb55a99ce59
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:00007fb559fdd028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fb55ac16090 RCX: 00007fb55a99ce59
RDX: 0000000000004040 RSI: 0000200000000140 RDI: 0000000000000004
RBP: 00007fb55aa32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb55ac16128 R14: 00007fb55ac16090 R15: 00007fffd4c56a68
 </TASK>