[CVE-2026-68113][MODERATE REGULAR] drm/amdgpu/gfx12: replace BUG_ON() with WARN_ON()

[AL-KERNEL <alkernel@kernelcve.org>]

CVE: CVE-2026-68113
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: drm/amdgpu/gfx12: replace BUG_ON() with WARN_ON()
Commit: eef69b826b2036314b59020dfa6083fc859bfcc1
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=eef69b826b2036314b59020dfa6083fc859bfcc1
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68113
Analysis date: Mon, 10 Aug 2026 15:26:13 -0400
ActionableScore: 3
ActionableScore lower bound: 2
Actionable bucket: Borderline, manual review recommended
Manual review required: YES

Summary:
AMDGPU gfx12 ring emission used BUG_ON() for alignment and fence flag checks, so a reachable malformed or inconsistent GPU submission state could panic the kernel and cause local denial of service, with no evidence of memory corruption or privilege escalation.

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ABOUT THIS REPORT
======================================================================

The original Linux kernel CVE announcement for CVE-2026-68113 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68113

The original announcement does not normally provide a security severity
estimate, CVSS assessment, or enough information to determine whether the
reported kernel bug represents a practically relevant security issue.

This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin. It combines
an autonomous classifier with LLM-assisted technical analysis and a
separate ActionableScore mechanism.

The purpose of this report is to prioritize Linux kernel CVEs before
manual review, identify cases that require prompt investigation, and
support automatic closure of issues that are unlikely to have meaningful
security impact.

Published priority for this report: MODERATE REGULAR
Manual review required: YES

A detailed explanation of the methodology and priority rules is included
at the end of this message.

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AL-KERNEL CLASSIFICATION RESULT
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CVE-2026-68113	MODERATE	CHECK WITH IMPACT FROM ORIG NN LOW	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H';CWE-617;CWE-754;**CWE-400;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.5';DESCR 'AMDGPU gfx12 ring emission used BUG_ON() for several alignment and fence flag checks. If these checks are reachable from a malformed GPU job or from an inconsistent driver state, the kernel can panic and the system can be crashed. For the CVSS the PR:L is used because triggering may be possible from a local user with access to DRM render or GPU submission interfaces rather than requiring full administrator privileges. The issue is not network reachable. Impact is denial of service only because the patch shows assertion based crashes and does not show a UAF, OOB write, information leak, or other memory corruption primitive.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline, manual review recommended (with actual score 3)  SKIP CVE-2026-68113 UNKNOWN SKIP No affected files built, so skip this CVE NO  - - unknown 	MAYBE	OOB DANGER SIMPLEFIX KERNEL_PANIC_PLUS_UAF HARDWARE PACKET  DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH	-	-	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=3
ActionableScoreLower=2

## 1. ActionableScore

* Conservative score: 2
* Paranoid score: 3
* Final recommended bucket: **Borderline, manual review recommended**

## 2. Signal breakdown

Conservative signals:

* Local unprivileged trigger: +1
  AMDGPU render nodes are commonly accessible to local desktop or compute users, but the patch does not prove that an unprivileged userspace submission can directly create the misaligned IB or fence state.

* Reliable kernel crash / strong DoS: +1
  The removed BUG_ON() checks can panic the kernel if reached.

Paranoid additional signal:

* Availability impact realistic: +1
  If the checked conditions are reachable through normal DRM or render-node GPU submission, the impact is a host-wide kernel panic rather than a limited device failure.

Signals not applied:

* Generic memory corruption: +0
  The patch shows assertion-to-warning changes only. It does not show UAF, OOB write, double free, refcount misuse, type confusion, or arbitrary write.

* Privilege escalation plausible: +0
  No LPE primitive is supported by the diff.

* Local high-control kernel data-plane API: +0
  GPU object submission alone is not enough under the provided rule. The patch does not show attacker control over lifetime, reclaim, callback targets, DMA ownership, or memory layout.

* Network reachable: +0
  This is a local DRM/GPU driver path, not a network path.

## 3. Reachability analysis

A local user with access to AMDGPU DRM render or GPU submission interfaces is the most plausible attacker. In typical desktop or GPU compute deployments, `/dev/dri/renderD*` may be accessible to non-root users in the `render` or similar group, so PR:L is a reasonable paranoid interpretation.

The affected code is hardware and driver specific to AMDGPU gfx12. It is not universally enabled on all systems, but it is reachable on systems using affected AMD GPUs and the amdgpu driver. Namespaces do not automatically make this broadly reachable unless the DRM device node is passed into a container.

The key uncertainty is whether userspace can actually cause `addr0`, `ib->gpu_addr`, fence `addr`, or KIQ fence flags to violate these assertions after earlier driver validation. That call-path reachability is not proven by the patch.

Call-site confidence: medium. The changed functions are visible and clearly in ring emission paths, but the userspace-to-condition path is not shown.

## 4. Severity interpretation

This behaves like a local DoS issue rather than an Important-class memory corruption vulnerability. The theoretical impact is a kernel panic via reachable BUG_ON(), but there is no evidence of confidentiality impact, integrity impact, or privilege escalation.

The conservative score is Low-like / ordinary Moderate. The paranoid score is Borderline because local unprivileged reachability through DRM render nodes is plausible enough to justify manual confirmation.

## 5. One-sentence report phrase

AMDGPU gfx12 ring emission used BUG_ON() for alignment and fence flag checks, so a reachable malformed or inconsistent GPU submission state could panic the kernel and cause local denial of service, with no evidence of memory corruption or privilege escalation.

## 6. Manual review recommendation

MANUAL CHECK RECOMMENDED

The issue should be checked manually to confirm whether an unprivileged local user with DRM render-node access can reach the removed BUG_ON() conditions on affected gfx12 hardware.

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UPSTREAM PATCH SUMMARY
======================================================================

Patch: drm/amdgpu/gfx12: replace BUG_ON() with WARN_ON()
Commit: eef69b826b2036314b59020dfa6083fc859bfcc1
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=eef69b826b2036314b59020dfa6083fc859bfcc1

Commit description:

There's no need to crash the kernel for these cases.

Reviewed-by: Vitaly Prosyak <vitaly.prosyak@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit f952076 )
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/gpu/drm/amd/amdgpu/gfx_v12_0.c

Diff excerpt:

Not included in this email. See the upstream URL for the full patch.

Full patch:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=eef69b826b2036314b59020dfa6083fc859bfcc1

======================================================================
DETAILED REPORT METHODOLOGY
======================================================================

The original Linux kernel CVE announcement for CVE-2026-68113 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68113

The original CVE announcement normally does not include a security-level
estimate. In particular, it may not contain a CVSS assessment, an impact
level, or enough information to determine whether the reported bug is a
practically relevant security issue. One purpose of this parallel CVE list
is to provide that missing technical and prioritization information.

The original goal of the AL-KERNEL project was to prioritize Linux kernel
CVE analysis automatically before manual review. The system can also help
identify non-security issues that may be suitable for automatic closure.

This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin.

The first analysis stage combines an autonomous classifier with additional
LLM-based analysis. The autonomous classifier runs locally on a CPU and is
based on a backpropagation neural network. Together, these mechanisms
produce a technical vulnerability description, identify likely weakness
types, estimate CVSS severity, and provide input for ActionableScore.

Two CVSS estimates are retained because incomplete kernel vulnerability
information often permits more than one defensible interpretation:

  Conservative CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 5.5

The conservative vector represents a lower-impact interpretation.
The Best/paranoid vector intentionally represents a plausible upper-bound
interpretation and should not automatically be treated as demonstrated
real-world impact.

CVSS may also need to be adjusted for a particular Linux deployment,
because actual reachability, privileges, enabled kernel configuration,
hardware, namespaces, exposed device nodes, and other environmental
conditions can differ significantly between systems.

A separate ActionableScore mechanism evaluates practical remediation
urgency. Its analysis may include reachability, attack prerequisites,
subsystem exposure, memory-corruption characteristics, denial-of-service
reliability, and possible confidentiality, integrity, or
privilege-escalation impact.

  Conservative ActionableScore: 2
  Paranoid ActionableScore: 3

The final base severity is taken directly from the second tab-separated
field of the AL-KERNEL classification result. ActionableScore does not
replace or independently override that final AL-KERNEL decision, and
if ActionableScore adjusted impact level of ALKERNEL, then you would see
self-readable flags above like INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7.

For an AL-KERNEL result of MODERATE, this report uses the following
additional presentation split:

  ActionableScore below 5   -> MODERATE REGULAR
  ActionableScore 5 or more -> MODERATE 7.0

The distinction between MODERATE REGULAR and MODERATE 7.0 makes it
possible to identify Moderate issues that should receive manual analysis
and fixes before lower-priority MODERATE REGULAR issues. In many cases,
MODERATE REGULAR fixes may wait for a later rebase or routine update.

There is one override in which MODERATE REGULAR becomes MODERATE 7.0
even when the ActionableScore is below 5. When the AL-KERNEL result
contains the KPANIC flag, a MODERATE result is always presented as
MODERATE 7.0. The KPANIC flag selected with few regexps without
usage of AI at all, so it helps to detect cases when Kernel Crash happens
and similar (to filter False-Negative results from the LLM usage).

KPANIC indicates that a reliable kernel crash, kernel panic, or similarly
serious kernel availability impact was identified by the classification
workflow.

AL-KERNEL base severity for this report: MODERATE
KPANIC detected for this report: NO
Published priority for this report (same as in Subject): MODERATE REGULAR

These results are intended to support engineering triage. They are
machine-generated estimates, and cases marked for manual review should
be validated by a human security engineer before final disposition.
For more info read docs linked from here: https://kernelcve.org/
(and you can submit you own patch there to generate such a report
for non-existant CVE-id yet).

Note that in many cases this AI tool selects higher severity, than
real is (means you can expect Importants instead of Moderate 7.0 or
Moderates 7.0 instead of regular Moderates). If you see such cases,
please use reply email interface to add additional manual analyses
info to this particular CVE.
And please, please, let me know when you see Lows instead of Importants
or Important instead of Low (because particular for such cases I
need to tune this AI tool to make it better for this one and next similar).
My contact email for such notifications is alexanjelausa@gmail.com (and both
send reply to CVE record itself too and see "reply" button below for howto reply).