VirtualBox 5.1.26 crashes when using VLAN in linux guest over Internal Network

[RomanovR]

VirtualBox 5.1.26 crashes when using VLAN in linux guest over Internal Network. After 5-10 mins launching VM guest in Host console I hane an error:

NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [EMT-0:19382]

The same bug was in 5.1.24 version and it there are only when using VLAN in guest VM via Internal Network in Host. Portion of logs attached (log in Host)

[RomanovR]

Logs from LInux Host for problem of using VLAN with Ineternal Network

[Valery Ushakov]

Please, can you describe the scenario in more details? I left two VMs pinging each other over internal network with vlan configured and they happily survived for a couple of hours. Do I need more load or some specific load to trigger this?

Also, I can quite parse the last paragraph. What is the difference between 5.1.24 and 5.1.26 that you are trying to describe there?

[toMeloos]

Would like to confirm this issue.

Been using VirtualBox 5.1.8 on Fedora 25 without any problem for months. Then tried VB 5.1.26 on both F25, F26 and the latest CentOS 7 (both with the stock 3.10 and mainline 4.12 kernel) on a HP Z800 and a Dell PowerEdge r610 and we get the CPU soft lockup issue on both. Downgraded back to 5.1.8 and the problem disappears, so we are now happily running that again on CentOS 7 with the stock 3.10 kernel. We have not tested the VB versions between 5.1.8 and 5.1.26.

Our VM's have 4 vCPU and 16 GB ram and run Ubuntu 16.04. They run in a cluster that uses VLANs over VirtualBox Internal Networks for traffic between nodes. We have two separate VirtualBox Internal Networks that both host a few VLANs.

A while after our second VM comes up, the NMI watchdog starts sending error messages to stdout. I'm pretty sure this is around the time puppet on the second machine has configured networking and services and they start generating network traffic. Very soon after, the second VM crashes/gets killed and we're stuck with a defunct VirtualBox process and the watchdog still generating warnings. Only solution is to reboot the host. What's also really weird is that the NMI watchdog warnings show up even after we disabled the NMI watchdog on both the host and the guests.