[CVE-2026-68244][MODERATE REGULAR] drm/i915/gem: Do not leak siblings[] on proto context error

[CVE-2026-68244][MODERATE REGULAR] drm/i915/gem: Do not leak siblings[] on proto context error

[AL-KERNEL]

CVE: CVE-2026-68244
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: drm/i915/gem: Do not leak siblings[] on proto context error
Commit: f014702fbd48d06a3d7a06e4bb4075d406376cf0
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f014702fbd48d06a3d7a06e4bb4075d406376cf0
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68244
Analysis date: Mon, 10 Aug 2026 16:44:35 -0400
ActionableScore: 3
ActionableScore lower bound: 2
Actionable bucket: Ordinary Moderate / Low-like, not an Important candidate
Manual review required: NO

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-68244 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68244

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: NO

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

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

CVE-2026-68244	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-401;*CWE-772;**CWE-400;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.5';DESCR 'i915 GEM context creation can leak per engine siblings arrays when a BALANCE or PARALLEL_SUBMIT extension succeeds and a later user extension fails. This is a local resource leak in the DRM control path and can accumulate kernel memory across repeated failed context creation attempts. For the CVSS the PR:L is used because a local process needs access to the i915 DRM device and must issue context creation ioctls. The issue is not network reachable. Impact is denial of service through memory exhaustion only, with no supported evidence of information disclosure or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like, not an Important candidate (with actual score 3)  SKIP CVE-2026-68244 UNKNOWN SKIP No affected files built, so skip this CVE NO  - - unknown 	MAYBE	SIMPLEFIX LEAK HARDWARE  INCREASED_FROM_LOW_BASED_ON_HIGHCVSSSCORE DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5	-	-	checked

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

ActionableScore=3
ActionableScoreLower=2

1. **ActionableScore**
* Conservative score: 2
* Paranoid score: 3
* Final recommended bucket: **Ordinary Moderate / Low-like, not an Important candidate**::

2. **Signal breakdown**
* Local unprivileged trigger: +1. i915 GEM context creation is reachable through DRM ioctls, often via local render node access.
* Availability impact realistic: +1. Repeated failed context creation can leak kernel memory and may eventually cause resource exhaustion.
* Broad/default/common subsystem: +1 in paranoid score only. i915 is widely deployed on Intel GPU systems and render nodes are commonly exposed to local users.
* No generic memory corruption: +0. The patch fixes a missing `kfree()` for nested `siblings[]` arrays, not UAF, double-free, OOB write, type confusion, or refcount misuse.
* No privilege escalation plausible: +0. No reclaim, overwrite, stale callback, object confusion, credential impact, or file-backed/page-cache corruption is shown.
* No remote reachability: +0. This is a local DRM control path issue.

3. **Reachability analysis**
A local process with access to the i915 DRM device can trigger the error path by creating a proto context with a successful BALANCE or PARALLEL_SUBMIT extension followed by a failing later extension. In many desktop or GPU-enabled systems, render node access may be available to non-root users, so PR:L is reasonable. Containers only matter if the DRM device is passed through. The path is not network reachable and depends on Intel i915 hardware and exposed DRM device nodes.

4. **Severity interpretation**
This behaves like an ordinary Moderate or Low-like resource leak, not an Important-class vulnerability. The realistic impact is sustained local DoS through memory exhaustion after repeated attempts. There is no supported memory corruption primitive and no evidence of confidentiality, integrity, or privilege-escalation impact.

5. **One-sentence report phrase**
A local user with access to the i915 DRM device can repeatedly trigger an error path in GEM proto context creation that leaks `siblings[]` arrays, potentially causing kernel memory exhaustion but not showing evidence of memory corruption or privilege escalation.

6. **Manual review recommendation**
NO MANUAL CHECK NEEDED

Reason: this is a straightforward memory leak on an error path with no UAF, overwrite, type confusion, security-boundary bypass, or remote exposure indicated by the patch.

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

Patch: drm/i915/gem: Do not leak siblings[] on proto context error
Commit: f014702fbd48d06a3d7a06e4bb4075d406376cf0
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f014702fbd48d06a3d7a06e4bb4075d406376cf0

Commit description:

After a successful BALANCE/PARALLEL_SUBMIT extension on context
creation, error during processing of next user extension leaks
the siblings[] array. Fix that.

Discovered using AI-assisted static analysis confirmed by
Intel Product Security.

Reported-by: Martin Hodo <martin.hodo@intel.com>
Fixes: d4433c7 ("drm/i915/gem: Use the proto-context to handle create parameters (v5)")
Cc: Faith Ekstrand <faith.ekstrand@collabora.com>
Cc: Simona Vetter <simona.vetter@ffwll.ch>
Cc: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: <stable@vger.kernel.org> # v5.15+
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>
Link: https://lore.kernel.org/r/20260701073030.44850-1-joonas.lahtinen@linux.intel.com
(cherry picked from commit aa65e0a )
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/gpu/drm/i915/gem/i915_gem_context.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=f014702fbd48d06a3d7a06e4bb4075d406376cf0

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

The original Linux kernel CVE announcement for CVE-2026-68244 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68244

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:L/PR:L/UI:N/S:U/C:N/I:N/A:L
  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).