ubuntu-24.04 amd64 runner kernel 6.17.0-1015-azure Oopses in ublk_drv

[ValentaTomas]

Description

The current ubuntu-24.04 amd64 hosted runner image ships kernel 6.17.0-1015-azure, which Oopses in ublk_drv on a single UBLK_U_CMD_ADD_DEV.

Minimal standalone repro:
https://github.com/e2b-dev/ublk-adddev-repro

Actions run:
https://github.com/e2b-dev/ublk-adddev-repro/actions

Observed:

• ubuntu-22.04 / 6.8.0-1052-azure: repro passes
• ubuntu-24.04 / 6.17.0-1015-azure: kernel Oops in ublk_init_queues and the command never completes

Oops excerpt:

RIP: 0010:ublk_init_queues+0x4e/0x1e0 [ublk_drv]
Call Trace:
ublk_ctrl_add_dev+0x31a/0x5e0 [ublk_drv]
ublk_ctrl_uring_cmd+0x7f/0x754 [ublk_drv]
io_uring_cmd+0xa3/0x140
io_wq_submit_work+0xcc/0x330
io_wq_worker+0xfd/0x380
note: iou-wrk-* exited with irqs disabled

This breaks CI for projects testing Linux ublk on hosted runners. We temporarily pinned amd64 integration to ubuntu-22.04 to avoid the broken kernel.

Platforms affected

• Azure DevOps
• GitHub Actions - Standard Runners
• GitHub Actions - Larger Runners

Runner images affected

• Ubuntu 22.04
• Ubuntu 24.04
• Ubuntu Slim
• macOS 14
• macOS 14 Arm64
• macOS 15
• macOS 15 Arm64
• macOS 26
• macOS 26 Arm64
• Windows Server 2022
• Windows Server 2025
• Windows Server 2025 with Visual Studio 2026

Image version and build link

Current runner version: '2.334.0'
Runner Image Provisioner
Hosted Compute Agent
Version: 20260520.533
Commit: 189110e25284a9812c124fd27b339e2fb4f2f9db
Build Date: 2026-05-20T17:44:04Z
Worker ID: {8384fdc7-2787-4abd-891e-1bb1ca508b1f}
Azure Region: eastus2
Operating System
Ubuntu
24.04.4
LTS
Runner Image
Image: ubuntu-24.04
Version: 20260525.161.1
Included Software: https://github.com/actions/runner-images/blob/ubuntu24/20260525.161/images/ubuntu/Ubuntu2404-Readme.md
Image Release: https://github.com/actions/runner-images/releases/tag/ubuntu24%2F20260525.161
GITHUB_TOKEN Permissions
Secret source: Actions
Prepare workflow directory
Prepare all required actions
Getting action download info
Download action repository 'actions/checkout@v6.0.2' (SHA:de0fac2e4500dabe0009e67214ff5f5447ce83dd)
Complete job name: repro (ubuntu-24.04)

Is it regression?

Yes. The same standalone repro passes on ubuntu-22.04 hosted runners with kernel 6.8.0-1052-azure. Known passing run: https://github.com/e2b-dev/ublk-adddev-repro/actions The failing image is ubuntu-24.04 version 20260525.161.1 with kernel 6.17.0-1015-azure.

Expected behavior

A single UBLK_U_CMD_ADD_DEV should either complete successfully or return an error CQE. It should not Oops the kernel or leave the userspace process stuck waiting for a completion.

Actual behavior

On ubuntu-24.04 amd64 runners, the repro triggers a kernel Oops in ublk_drv:

RIP: ublk_init_queues+0x4e/0x1e0 [ublk_drv]
Call Trace:
ublk_ctrl_add_dev
ublk_ctrl_uring_cmd
io_uring_cmd
io_wq_submit_work
io_wq_worker

After the Oops, the ADD_DEV command never completes, so userspace waits indefinitely. The same repro passes on ubuntu-22.04.

Repro steps

Public minimal repro repo:
https://github.com/e2b-dev/ublk-adddev-repro

Workflow:
https://github.com/e2b-dev/ublk-adddev-repro/actions

Manual steps on an ubuntu-24.04 amd64 hosted runner:

1. Check out the repro repo.
2. Load ublk_drv:
   sudo modprobe ublk_drv || {
   sudo apt-get update -qq
   sudo apt-get install -y --no-install-recommends "linux-modules-extra-$(uname -r)"
   sudo modprobe ublk_drv
   }
3. Build:
   make
4. Run:
   sudo ./ublk_add_dev_repro
5. Check dmesg for the ublk_init_queues Oops.

[v-GeorgyPuzakov]

Hi @ValentaTomas, thanks for the minimal repro.

This is an upstream linux-azure kernel bug, not a runner-images regression. We don't pin the kernel — it comes from Canonical's channel, and ublk_drv ships in linux-modules-extra-$(uname -r).

Kernel diff:

• ubuntu-22.04 → 6.8.0-1052-azure (works)
• ubuntu-24.04 20260525.161.1 → 6.17.0-1015-azure (Oops in ublk_init_queues)

Big HWE jump (6.8 → 6.17), and the ublk_init_queues+0x4e crash on a single UBLK_U_CMD_ADD_DEV has to be fixed in the kernel.

Please file upstream:

• Canonical: https://bugs.launchpad.net/ubuntu/+source/linux-azure/+filebug
• If reproducible on mainline 6.17: linux-block@vger.kernel.org (maintainer: Ming Lei)

Your repro is exactly what they need.

Workaround: stay on ubuntu-22.04 for the ublk job (you already did). A fixed linux-azure SRU will be picked up automatically.

We can't ship an image-side fix — pinning kernels would diverge from Canonical's security/HWE channel. Leaving open as a tracking issue.

[khayyamsaleem]

submitted the launchpad bug: https://bugs.launchpad.net/ubuntu/+source/linux-azure/+bug/2154635