# CVE-2026-23163: drm/amdgpu: fix NULL pointer dereference in amdgpu_gmc_filter_faults_remove

> A NULL pointer dereference in the amdgpu driver causes a kernel crash on APUs when retry faults are enabled, leading to denial of service.

- **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:** 14 Feb 2026
- **Updated:** 11 May 2026
- **Also known as:** AZL-77760, BELL-CVE-2026-23163, DEBIAN-CVE-2026-23163, GHSA-3x2r-29rp-vh66, ROOT-OS-UBUNTU-2404-CVE-2026-23163, UBUNTU-CVE-2026-23163

## What is CVE-2026-23163?

CVE-2026-23163 is a medium-severity vulnerability in Linux kernel, published on 14 Feb 2026. 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:

drm/amdgpu: fix NULL pointer dereference in amdgpu_gmc_filter_faults_remove

On APUs such as Raven and Renoir (GC 9.1.0, 9.2.2, 9.3.0), the ih1 and
ih2 interrupt ring buffers are not initialized. This is by design, as
these secondary IH rings are only available on discrete GPUs. See
vega10_ih_sw_init() which explicitly skips ih1/ih2 initialization when
AMD_IS_APU is set.

However, amdgpu_gmc_filter_faults_remove() unconditionally uses ih1 to
get the timestamp of the last interrupt entry. When retry faults are
enabled on APUs (noretry=0), this function is called from the SVM page
fault recovery path, resulting in a NULL pointer dereference when
amdgpu_ih_decode_iv_ts_helper() attempts to access ih->ring[].

The crash manifests as:

  BUG: kernel NULL pointer dereference, address: 0000000000000004
  RIP: 0010:amdgpu_ih_decode_iv_ts_helper+0x22/0x40 [amdgpu]
  Call Trace:
   amdgpu_gmc_filter_faults_remove+0x60/0x130 [amdgpu]
   svm_range_restore_pages+0xae5/0x11c0 [amdgpu]
   amdgpu_vm_handle_fault+0xc8/0x340 [amdgpu]
   gmc_v9_0_process_interrupt+0x191/0x220 [amdgpu]
   amdgpu_irq_dispatch+0xed/0x2c0 [amdgpu]
   amdgpu_ih_process+0x84/0x100 [amdgpu]

This issue was exposed by commit 1446226d32a4 ("drm/amdgpu: Remove GC HW
IP 9.3.0 from noretry=1") which changed the default for Renoir APU from
noretry=1 to noretry=0, enabling retry fault handling and thus
exercising the buggy code path.

Fix this by adding a check for ih1.ring_size before attempting to use
it. Also restore the soft_ih support from commit dd299441654f ("drm/amdgpu:
Rework retry fault removal").  This is needed if the hardware doesn't
support secondary HW IH rings.

v2: additional updates (Alex)

(cherry picked from commit 6ce8d536c80aa1f059e82184f0d1994436b1d526)

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-23163?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23163?

Apply the vendor's patch.

## Is CVE-2026-23163 being exploited?

There is no known exploitation of CVE-2026-23163 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-2026-23163 and fix it if it is affected.

What it is: CVE-2026-23163 is a medium-severity vulnerability in Linux kernel, published on 14 Feb 2026. 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-2026-23163 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-2026-23163/ (Markdown: https://insights.sbomify.com/CVE-2026-23163/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23163
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23163
- OSV: https://osv.dev/vulnerability/CVE-2026-23163

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23163/
Summaries are generated and may contain mistakes; the official description above is the record.