------------[ cut here ]------------
'send_pkt()' returns 0, but 65536 expected
WARNING: CPU: 0 PID: 6070 at net/vmw_vsock/virtio_transport_common.c:426 virtio_transport_send_pkt_info+0x91d/0x1020 net/vmw_vsock/virtio_transport_common.c:426
Modules linked in:
CPU: 0 UID: 0 PID: 6070 Comm: syz.3.7 Not tainted 6.16.0-syzkaller-12063-g37816488247d #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:virtio_transport_send_pkt_info+0x91d/0x1020 net/vmw_vsock/virtio_transport_common.c:426
Code: a9 8d 4b f6 84 db 75 26 e8 c0 92 4b f6 c6 05 4f 28 24 05 01 90 48 8b 54 24 10 44 89 ee 48 c7 c7 e0 35 13 8d e8 14 84 0a f6 90 <0f> 0b 90 90 e8 9a 92 4b f6 31 ff 44 89 e6 e8 d0 8d 4b f6 45 85 e4
RSP: 0018:ffffc90003c77710 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000cc04000
RDX: 0000000000080000 RSI: ffffffff817a02d5 RDI: 0000000000000001
RBP: ffff88805f327400 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000010000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000010000
FS:  0000000000000000(0000) GS:ffff8880974cb000(0063) knlGS:00000000f550eb40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000008003f000 CR3: 000000006cf76000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 virtio_transport_stream_enqueue net/vmw_vsock/virtio_transport_common.c:1111 [inline]
 virtio_transport_seqpacket_enqueue+0x13c/0x1c0 net/vmw_vsock/virtio_transport_common.c:839
 vsock_connectible_sendmsg+0xf9e/0x1280 net/vmw_vsock/af_vsock.c:2140
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg net/socket.c:729 [inline]
 ____sys_sendmsg+0xa98/0xc70 net/socket.c:2614
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
 __sys_sendmmsg+0x2f9/0x420 net/socket.c:2750
 __compat_sys_sendmmsg net/compat.c:360 [inline]
 __do_compat_sys_sendmmsg net/compat.c:367 [inline]
 __se_compat_sys_sendmmsg net/compat.c:364 [inline]
 __ia32_compat_sys_sendmmsg+0x9d/0x100 net/compat.c:364
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x3a0 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf711e579
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:00000000f550e55c EFLAGS: 00000296 ORIG_RAX: 0000000000000159
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000080000100
RDX: 0000000000000001 RSI: 0000000024008094 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
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