[CVE-2026-68246][MODERATE REGULAR] drm/amdgpu/gfx11: replace BUG_ON() with WARN_ON()

[CVE-2026-68246][MODERATE REGULAR] drm/amdgpu/gfx11: replace BUG_ON() with WARN_ON()

[AL-KERNEL]

CVE: CVE-2026-68246
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: drm/amdgpu/gfx11: replace BUG_ON() with WARN_ON()
Commit: 96b6d68f2b5a208e4d8f1e4a932ec424655e1267
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=96b6d68f2b5a208e4d8f1e4a932ec424655e1267
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68246
Analysis date: Mon, 10 Aug 2026 10:50:44 -0400
ActionableScore: 3
ActionableScore lower bound: 2
Actionable bucket: Borderline Moderate / manual review recommended
Manual review required: YES

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-68246 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68246

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.

======================================================================
AL-KERNEL CLASSIFICATION RESULT
======================================================================

CVE-2026-68246	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-703;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.5';DESCR 'A reachable BUG_ON() in the amdgpu gfx11 ring emission path can turn invalid alignment or fence flag states into a full kernel panic. A local user with access to AMDGPU submission paths may be able to trigger the condition if an unaligned IB GPU address or invalid fence state can pass earlier validation. For the CVSS the PR:L is used because practical triggering would require local code execution and access to DRM or render node interfaces rather than administrative privileges. The issue is not network reachable and has no clear memory corruption primitive in the shown diff. Impact is denial of service via kernel crash only.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline Moderate / manual review recommended (with actual score 3)  SKIP CVE-2026-68246 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

======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================

ActionableScore=3
ActionableScoreLower=2

1. ActionableScore
* Conservative score: 2
* Paranoid score: 3
* Final recommended bucket: **Borderline Moderate / manual review recommended**::

2. Signal breakdown
* Local unprivileged trigger: +1. AMDGPU command submission paths may be reachable by local users through DRM render nodes, but exact reachability of these specific alignment and fence states needs call-site review.
* Reliable kernel crash / strong DoS: +1. The original code used BUG_ON(), so if the condition is reachable it can panic the kernel.
* Broad/default/common subsystem or broadly deployed exposure: +1 in paranoid score only. AMDGPU is common on systems with AMD GPUs, but the affected code is gfx11-specific and hardware-dependent.
* No generic memory corruption: +0. The patch replaces BUG_ON() with WARN_ON() and removes one assertion. It does not show UAF, OOB write, type confusion, refcount misuse, or attacker-controlled overwrite.
* No privilege escalation plausible signal: +0. There is no demonstrated corruption primitive or control-flow/data overwrite path.
* No confidentiality or integrity impact: +0. The shown failure mode is crash/assertion behavior only.
* No high-control kernel data-plane API bonus: +0. GPU ioctls/render nodes alone are not enough without evidence of attacker control over lifetime, allocator behavior, DMA ownership, or memory layout.
* Call-site confidence: medium. The patch shows the assertion sites but not enough surrounding validation/call paths to prove whether unprivileged users can pass misaligned IB or fence state into these functions.

3. Reachability analysis
A local user with access to AMDGPU DRM/render-node submission paths is the most plausible trigger candidate. No network reachability is indicated. Namespaces do not materially reduce the requirement unless the container or sandbox exposes the relevant DRM device node to an untrusted user. The path is default-enabled only on affected AMD gfx11 hardware with the amdgpu driver in use. Realistic exploitation depends on whether earlier amdgpu validation can be bypassed or whether normal error paths can naturally produce the invalid alignment or fence flag state.

4. Severity interpretation
This behaves like an ordinary-to-borderline Moderate local DoS issue, not an Important-class vulnerability. The theoretical impact is a full kernel panic through reachable BUG_ON(), but the patch does not support memory corruption, privilege escalation, information disclosure, or persistent integrity damage. The main uncertainty is triggerability from unprivileged DRM users.

5. One-sentence report phrase
A reachable BUG_ON() in AMDGPU gfx11 ring emission paths could allow a local user with access to GPU submission interfaces to trigger a kernel panic if invalid alignment or fence state reaches these checks.

6. Manual review recommendation
MANUAL CHECK RECOMMENDED.
Review should verify whether unprivileged render-node users can influence `ib->gpu_addr`, fence addresses, or `AMDGPU_FENCE_FLAG_64BIT` enough to reach the former BUG_ON() paths.

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

Patch: drm/amdgpu/gfx11: replace BUG_ON() with WARN_ON()
Commit: 96b6d68f2b5a208e4d8f1e4a932ec424655e1267
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=96b6d68f2b5a208e4d8f1e4a932ec424655e1267

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 daa6210 )
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/gpu/drm/amd/amdgpu/gfx_v11_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=96b6d68f2b5a208e4d8f1e4a932ec424655e1267

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

The original Linux kernel CVE announcement for CVE-2026-68246 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68246

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).