------------[ cut here ]------------
'send_pkt()' returns 0, but 4096 expected
WARNING: net/vmw_vsock/virtio_transport_common.c:430 at 0x0, CPU#0: syz.0.17/6517
Modules linked in:
CPU: 0 UID: 0 PID: 6517 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:virtio_transport_send_pkt_info+0xcc1/0xed0 net/vmw_vsock/virtio_transport_common.c:428
Code: 48 8b 74 24 20 ba 02 00 00 00 e8 ca 14 f6 fd 41 be f4 ff ff ff 4d 89 e5 e9 22 ff ff ff 48 8d 3d a5 78 90 04 44 89 f6 48 89 ea <67> 48 0f b9 3a 31 ff 89 de e8 61 46 7d f6 85 db 74 0a e8 18 42 7d
RSP: 0018:ffffc900035474e8 EFLAGS: 00010206
RAX: ffffffff8b44ae8f RBX: 0000000000001000 RCX: 0000000000000000
RDX: 0000000000001000 RSI: 0000000000000000 RDI: ffffffff8fd52a20
RBP: 0000000000001000 R08: ffffffff8fc3a677 R09: 1ffffffff1f874ce
R10: dffffc0000000000 R11: fffffbfff1f874cf R12: 0000000000040000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffffc90003547620
FS:  00007fc936ea66c0(0000) GS:ffff8881259ed000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000030000 CR3: 000000007bb9c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 virtio_transport_stream_enqueue net/vmw_vsock/virtio_transport_common.c:1113 [inline]
 virtio_transport_seqpacket_enqueue+0x143/0x1c0 net/vmw_vsock/virtio_transport_common.c:841
 vsock_connectible_sendmsg+0xabf/0x1040 net/vmw_vsock/af_vsock.c:2158
 sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737
 __sock_sendmsg net/socket.c:752 [inline]
 ____sys_sendmsg+0x577/0x880 net/socket.c:2610
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2664
 __sys_sendmmsg+0x227/0x430 net/socket.c:2753
 __do_sys_sendmmsg net/socket.c:2780 [inline]
 __se_sys_sendmmsg net/socket.c:2777 [inline]
 __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2777
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc935f8f749
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc936ea6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fc9361e5fa0 RCX: 00007fc935f8f749
RDX: 0000000000000001 RSI: 0000200000000100 RDI: 0000000000000004
RBP: 00007fc936013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000024008094 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc9361e6038 R14: 00007fc9361e5fa0 R15: 00007ffdbe72b4d8
 </TASK>
----------------
Code disassembly (best guess):
   0:	48 8b 74 24 20       	mov    0x20(%rsp),%rsi
   5:	ba 02 00 00 00       	mov    $0x2,%edx
   a:	e8 ca 14 f6 fd       	call   0xfdf614d9
   f:	41 be f4 ff ff ff    	mov    $0xfffffff4,%r14d
  15:	4d 89 e5             	mov    %r12,%r13
  18:	e9 22 ff ff ff       	jmp    0xffffff3f
  1d:	48 8d 3d a5 78 90 04 	lea    0x49078a5(%rip),%rdi        # 0x49078c9
  24:	44 89 f6             	mov    %r14d,%esi
  27:	48 89 ea             	mov    %rbp,%rdx
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	31 ff                	xor    %edi,%edi
  31:	89 de                	mov    %ebx,%esi
  33:	e8 61 46 7d f6       	call   0xf67d4699
  38:	85 db                	test   %ebx,%ebx
  3a:	74 0a                	je     0x46
  3c:	e8                   	.byte 0xe8
  3d:	18 42 7d             	sbb    %al,0x7d(%rdx)