# CVE-2023-53647: Drivers: hv: vmbus: Don't dereference ACPI root object handle

> A null pointer dereference in the Linux kernel VMBus driver causes a system crash during boot when Hyper-V MMIO ranges are missing.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 Oct 2025
- **Updated:** 11 May 2026
- **Also known as:** AZL-76413, BELL-CVE-2023-53647, DEBIAN-CVE-2023-53647, GHSA-c2mm-xf5x-8rpj, ROOT-OS-DEBIAN-11-CVE-2023-53647, ROOT-OS-UBUNTU-2204-CVE-2023-53647, UBUNTU-CVE-2023-53647

## What is CVE-2023-53647?

CVE-2023-53647 is a medium-severity vulnerability in Linux kernel, published on 7 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

Drivers: hv: vmbus: Don't dereference ACPI root object handle

Since the commit referenced in the Fixes: tag below the VMBus client driver
is walking the ACPI namespace up from the VMBus ACPI device to the ACPI
namespace root object trying to find Hyper-V MMIO ranges.

However, if it is not able to find them it ends trying to walk resources of
the ACPI namespace root object itself.
This object has all-ones handle, which causes a NULL pointer dereference
in the ACPI code (from dereferencing this pointer with an offset).

This in turn causes an oops on boot with VMBus host implementations that do
not provide Hyper-V MMIO ranges in their VMBus ACPI device or its
ancestors.
The QEMU VMBus implementation is an example of such implementation.

I guess providing these ranges is optional, since all tested Windows
versions seem to be able to use VMBus devices without them.

Fix this by explicitly terminating the lookup at the ACPI namespace root
object.

Note that Linux guests under KVM/QEMU do not use the Hyper-V PV interface
by default - they only do so if the KVM PV interface is missing or
disabled.

Example stack trace of such oops:
[ 3.710827] ? __die+0x1f/0x60
[ 3.715030] ? page_fault_oops+0x159/0x460
[ 3.716008] ? exc_page_fault+0x73/0x170
[ 3.716959] ? asm_exc_page_fault+0x22/0x30
[ 3.717957] ? acpi_ns_lookup+0x7a/0x4b0
[ 3.718898] ? acpi_ns_internalize_name+0x79/0xc0
[ 3.720018] acpi_ns_get_node_unlocked+0xb5/0xe0
[ 3.721120] ? acpi_ns_check_object_type+0xfe/0x200
[ 3.722285] ? acpi_rs_convert_aml_to_resource+0x37/0x6e0
[ 3.723559] ? down_timeout+0x3a/0x60
[ 3.724455] ? acpi_ns_get_node+0x3a/0x60
[ 3.725412] acpi_ns_get_node+0x3a/0x60
[ 3.726335] acpi_ns_evaluate+0x1c3/0x2c0
[ 3.727295] acpi_ut_evaluate_object+0x64/0x1b0
[ 3.728400] acpi_rs_get_method_data+0x2b/0x70
[ 3.729476] ? vmbus_platform_driver_probe+0x1d0/0x1d0 [hv_vmbus]
[ 3.730940] ? vmbus_platform_driver_probe+0x1d0/0x1d0 [hv_vmbus]
[ 3.732411] acpi_walk_resources+0x78/0xd0
[ 3.733398] vmbus_platform_driver_probe+0x9f/0x1d0 [hv_vmbus]
[ 3.734802] platform_probe+0x3d/0x90
[ 3.735684] really_probe+0x19b/0x400
[ 3.736570] ? __device_attach_driver+0x100/0x100
[ 3.737697] __driver_probe_device+0x78/0x160
[ 3.738746] driver_probe_device+0x1f/0x90
[ 3.739743] __driver_attach+0xc2/0x1b0
[ 3.740671] bus_for_each_dev+0x70/0xc0
[ 3.741601] bus_add_driver+0x10e/0x210
[ 3.742527] driver_register+0x55/0xf0
[ 3.744412] ? 0xffffffffc039a000
[ 3.745207] hv_acpi_init+0x3c/0x1000 [hv_vmbus]

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2023-53647?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53647?

Apply the vendor's patch.

## Is CVE-2023-53647 being exploited?

There is no known exploitation of CVE-2023-53647 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53647 and fix it if it is affected.

What it is: CVE-2023-53647 is a medium-severity vulnerability in Linux kernel, published on 7 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-53647 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-53647/ (Markdown: https://insights.sbomify.com/CVE-2023-53647/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53647
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53647
- OSV: https://osv.dev/vulnerability/CVE-2023-53647

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53647/
Summaries are generated and may contain mistakes; the official description above is the record.