Re: [syzbot] [kvm?] [net?] [virt?] WARNING in virtio_transport_send_pkt_info

[Hillf Danton]

> Date: Mon, 11 Aug 2025 11:59:30 -0700	[thread overview]
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    37816488247d Merge tag 'net-6.17-rc1' of git://git.kernel...
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=10b3b2f0580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=e143c1cd9dadd720
> dashboard link: https://syzkaller.appspot.com/bug?extid=b4d960daf7a3c7c2b7b1
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10f0f042580000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14855434580000

#syz test

--- x/net/vmw_vsock/virtio_transport_common.c
+++ y/net/vmw_vsock/virtio_transport_common.c
@@ -258,9 +258,7 @@ static struct sk_buff *virtio_transport_
 	size_t skb_len;
 
 	skb_len = VIRTIO_VSOCK_SKB_HEADROOM;
-
-	if (!zcopy)
-		skb_len += payload_len;
+	skb_len += payload_len;
 
 	skb = virtio_vsock_alloc_skb(skb_len, GFP_KERNEL);
 	if (!skb)
--