dev test from ubuntu_stress_smoke_tests cause VM crash with N-oem-6.10

[Po-Hsu Lin]

The dev stressor from ubuntu_stress_smoke_tests will cause test interrupt with Noble OEM 6.10 VM on openstack since 6.10.0-1003.3

With further investigation, this issue can be reproduced with a VM on a bare-metal. When this happens the VM will be terminated. (Bare-metal can pass with this test)

It's 100% reproducible with the following steps:
# On a bare-metal running with Noble
sudo apt install uvtool build-essential -y
sudo uvt-simplestreams-libvirt sync --source http://cloud-images.ubuntu.com/daily release=noble arch=amd64
SSH_KEY="$HOME/.ssh/id_rsa"
ssh-keygen -f $SSH_KEY -t rsa -N ''
sudo -u ubuntu uvt-kvm create oem610 release=noble arch=amd64 --memory 2048
sleep 60
ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o LogLevel=quiet -i .ssh/id_rsa ubuntu@`sudo uvt-kvm ip oem610`
# Inside the VM
sudo apt-add-repository ppa:canonical-kernel-team/ubuntu/proposed -y
sudo apt install kernel-testing--linux-oem-6.10--full--oem -y
sudo reboot
sleep 60
ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o LogLevel=quiet -i .ssh/id_rsa ubuntu@`sudo uvt-kvm ip oem610`
git clone https://github.com/ColinIanKing/stress-ng.git
cd stress-ng; make
sudo ./stress-ng -v -t 5 --dev 4 --dev-ops 3000 --ignite-cpu --syslog --verbose --verify --oomable
# VM will be terminated here, you will have to restart it.

Issue reported upstream: https://github.com/ColinIanKing/stress-ng/issues/407
From Colin's investigation it looks like a kernel issue

This issue can be reproduced with mainline kernel v6.10-rc4 (AMD64 debs are not available for v6.10-rc6)

[Po-Hsu Lin (cypressyew)]

This issue can be found with Oracular 6.10.0-4.4 AMD64 openstack instance as well.

[Colin Ian King (colin-king)]

Reproducer:

#include <fcntl.h>
#include <unistd.h>

int main(void)
{
  pid_t pid = fork();

  while (1) {
   int fd;

   fd = openat(AT_FDCWD, "/dev/dri/card1", O_WRONLY|O_NONBLOCK|O_SYNC);
   close(fd);
  }
}

[Colin Ian King (colin-king)]

Reported upstream: https://bugzilla.kernel.org/show_bug.cgi?id=219007

[Po-Hsu Lin (cypressyew)]

Thanks for the bug report and the reproducer!