[CVE-2026-68183][MODERATE 7.0] firmware: stratix10-svc: fix memory leaks and list corruption bugs [ Upstream

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

CVE: CVE-2026-68183
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: firmware: stratix10-svc: fix memory leaks and list corruption bugs [ Upstream
Commit: 95f702e372964aff486338783f49e28a40a53127
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=95f702e372964aff486338783f49e28a40a53127
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68183
Analysis date: Mon, 10 Aug 2026 14:57:57 -0400
ActionableScore: 5
ActionableScore lower bound: 3
Actionable bucket: Actionable Moderate at minimum
Manual review required: YES

Summary:
The Stratix10 service layer fixes a pmem lifetime mismatch and an erroneous list_del on the global svc_data_mem list head, which can cause memory leaks and kernel list corruption leading to local DoS, with weak but review-worthy escalation concern on affected firmware-management paths.

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

The original Linux kernel CVE announcement for CVE-2026-68183 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68183

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 7.0
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-2026-68183	MODERATE	CHECK WITH IMPACT FROM ORIG NN LOW	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H';*CWE-401;CWE-763;*CWE-664;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '7';DESCR 'The Stratix10 service layer can leak pmem objects when gen_pool_alloc fails and can corrupt the svc_data_mem list when stratix10_svc_free_memory is called for an address that is not found. The most concerning part is the erroneous list_del on the global list head because later list traversal or allocation can operate on corrupted list pointers and crash the kernel. For the CVSS the PR:L is used for the paranoid score because practical exposure may come from a reduced privilege service account or delegated firmware management path rather than full unrestricted root. The issue is not network reachable and requires local access to a Stratix10 related firmware or driver path. Impact is at least local denial of service via kernel crash and in worst case may allow confidentiality or integrity impact due to list corruption, so it should be reviewed manually.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 4)  SKIP CVE-2026-68183 UNKNOWN SKIP No affected files built, so skip this CVE NO  - - unknown 	MAYBE	SIMPLEFIX LEAK ERRORPATH LINUS  INCREASED_TO_MODERATE_FROM_LOW_BASED_ON_GUESSCVSS DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5	-	-	checked

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

ActionableScore=5
ActionableScoreLower=3

## 1. ActionableScore

* Conservative score: 3
* Paranoid score: 5
* Final recommended bucket: **Actionable Moderate at minimum**::

## 2. Signal breakdown

Conservative signals:

* Weak/indirect corruption candidate: +1
  The removed `list_del(&svc_data_mem)` operates on the global list head after a failed lookup, which can corrupt kernel list metadata.
* Real lifetime corruption: +1
  The patch changes `pmem` from devm-managed lifetime to explicit `kzalloc` and `kfree`, matching the list-managed object lifetime.
* Reliable kernel crash / strong DoS: +1
  A corrupted list head can cause later list traversal or list manipulation failures, likely leading to kernel crash or WARN/BUG conditions.
* Privileged kernel/device-management memory corruption path: +1
  The bug is in a firmware service layer and affects trusted kernel-side memory bookkeeping.
* Availability impact realistic: +1
  List corruption can affect later allocation/free paths, not just a single failed call.
* Rare AND difficult-to-reach subsystem/configuration: -1
  Intel Stratix10 service layer is hardware/platform specific.
* Requires privileged or driver-mediated access in typical deployments: -1
  There is no evidence of a direct unprivileged userspace trigger. Full -2 is not used because practical exposure may involve reduced-privilege firmware management services or delegated device-control paths.

Paranoid additional signals:

* Firmware-mediated external influence: +1
  The affected subsystem interacts with platform firmware and service clients, so malformed or unexpected firmware-service workflows may influence reachability.
* Weak LPE concern: +1
  The corrupted list head is a possible corruption sink, but there is no demonstrated reclaim, controlled overwrite, callback control, or arbitrary write primitive.

Not awarded:

* Remote reachable / network-triggerable: +0
  No network path is shown.
* Strong LPE plausibility: +0
  No controlled UAF reclaim, arbitrary write, type confusion, callback dispatch, or refcount takeover is shown.
* Strong memory corruption primitive: +0
  The patch shows list corruption, but not attacker-controlled payload or target selection.

## 3. Reachability analysis

The likely trigger is local and platform-specific, through Stratix10 service-layer users or kernel clients that allocate and free service memory. A direct unprivileged userspace interface is not shown in the patch, so the conservative view treats this as privileged or driver-mediated. Namespaces are unlikely to matter unless a product exposes firmware-management functionality to a container, service account, or reduced-capability root context. The path is not broadly default-exposed across normal Linux systems because it depends on Intel Stratix10 hardware and the relevant firmware driver being present.

Call-site confidence: medium. The changed functions are exported service-layer allocation/free helpers, but the full caller set is not included in the provided diff.

## 4. Severity interpretation

This is stronger than an ordinary memory leak because the patch also removes an invalid `list_del()` on the global list head, which is a real kernel list-corruption bug. Realistic impact is most likely local denial of service on affected Stratix10 platforms. Theoretical escalation risk exists only as a weak corruption concern because corrupted list metadata can sometimes become exploitable, but the patch does not show attacker-controlled object replacement, arbitrary write, or a direct privilege-escalation primitive. Therefore this is best treated as Actionable Moderate at minimum, not auto-closed, but not a strong Important candidate without additional call-path evidence.

## 5. One-sentence report phrase

The Stratix10 service layer fixes a pmem lifetime mismatch and an erroneous list_del on the global svc_data_mem list head, which can cause memory leaks and kernel list corruption leading to local DoS, with weak but review-worthy escalation concern on affected firmware-management paths.

## 6. Manual review recommendation

YES REQUIRES MANUAL CHECK

MANUAL CHECK REQUIRED. The issue includes explicit kernel list corruption in a firmware service layer, and although the likely impact is DoS, the affected allocation/free helper should be manually checked at call sites for attacker influence over `kaddr`, object lifetime, and repeated triggerability.

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

Patch: firmware: stratix10-svc: fix memory leaks and list corruption bugs [ Upstream
Commit: 95f702e372964aff486338783f49e28a40a53127
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=95f702e372964aff486338783f49e28a40a53127

Changed files:
  drivers/firmware/stratix10-svc.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=95f702e372964aff486338783f49e28a40a53127

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

The original Linux kernel CVE announcement for CVE-2026-68183 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68183

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:H/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
  The Best / paranoid CVSS score: 7

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: 3
  Paranoid ActionableScore: 5

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 7.0

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).