[CVE-2026-93070][MODERATE 7.0] media: ipu6: Do not free aux device pdata after init [ Upstream

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

CVE: CVE-2026-93070
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: media: ipu6: Do not free aux device pdata after init [ Upstream
Commit: faa1eb97f0e66bf122f44b62be6b323f86333e9f
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=faa1eb97f0e66bf122f44b62be6b323f86333e9f
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93070
Analysis date: Thu, 17 Sep 2026 13:13:02 -0400
ActionableScore: 6
ActionableScore lower bound: 5
Actionable bucket: Actionable Moderate / Strong Important candidate requiring manual review
Manual review required: YES

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-93070 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93070

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.

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AL-KERNEL CLASSIFICATION RESULT
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CVE-2026-93070	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-93070 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:H/UI:N/S:U/C:H/I:H/A:H';CWE-415;*CWE-416;CWE-763;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '6.4';DESCR 'A double free can occur in the Intel IPU6 media driver error paths after ipu6_bus_initialize_device transfers ownership of pdata to the auxiliary device. An MMU initialization failure or auxiliary device add failure can invoke the device release callback which frees pdata, while the caller subsequently frees the same object again. This is a local heap memory corruption issue that can at least cause a kernel crash. For the CVSS the PR:H because reliable triggering normally requires administrative control over the IPU6 PCI driver lifecycle or device reinitialization and access to a rare initialization failure path. No direct network attack vector is indicated. The paranoid impact considers potential confidentiality and integrity effects because a kernel heap double free is a memory corruption primitive, but privilege escalation is not demonstrated by the patch context.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate / Strong Important candidate requiring manual review (with actual score 6)  SKIP CVE-2026-93070 UNKNOWN SKIP The Fixes patch not applied yet, so unlikely that actual: url YES  NO NO unknown 	MAYBE	SIMPLEFIX HARDWARE  KPANIC INCREASED_TO_MODERATE7_FROM_LOW_BASED_ON_GUESSCVSS_AND_ACTIONABLESCOREHIGHER4 KPANIC INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHERTHAN5 DECREASED_TO_MODERATE7_BASED_ON_FALSEPOSCHECKOFDH	-	-	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=6
ActionableScoreLower=5
PrimitiveClass=CLASS_B
RealUAF=YES
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=YES
ManualReview=REQUIRED
AutoDowngradeAllowed=NO

1. ActionableScore

* Raw conservative score: 4
* Conservative score: 5
* Raw paranoid score: 5
* Paranoid score: 6
* Conservative FLOOR 5 applied: 4 -> 5 because the patch establishes a concrete second lifetime-mutating free of the exact pdata reference after an earlier release path may already have freed it.
* Paranoid repeated-release leverage applied: 5 -> 6 because the second kfree operates on storage whose original object lifetime may have ended. This is an unresolved post-lifetime allocator mutation, not merely theoretical heap reuse.
* Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**::

2. Signal breakdown

Positive signals:

* +2 Real UAF or lifetime violation. `put_device()` or `auxiliary_device_uninit()` can invoke the auxiliary-device release callback, which frees `adev->pdata`. The caller still retains the exact `pdata` pointer and subsequently executes `kfree(pdata)`.
* +1 Concrete repeated release/refcount operation. The first lifetime operation can free pdata through `ipu6_bus_release()`. The same pointer remains reachable in the caller. The second operation is a concrete `kfree(pdata)` and is a real lifetime-mutating operation.
* +1 Reliable kernel crash or strong DoS. A kernel heap double free can trigger allocator consistency checks, an Oops, or kernel crash. This is counted once only.
* +1 Paranoid repeated-release leverage. The second `kfree()` can mutate allocator state through a dangling pointer after the first release has ended the original pdata lifetime. This is a technically grounded unresolved corruption mechanism.

Important non-awarded signals:

* Controlled reclaim or attacker-controlled object replacement is not demonstrated.
* Arbitrary or directed kernel write is not demonstrated.
* Callback or function-pointer control is not demonstrated.
* Confidentiality and integrity consequences are not awarded merely because a double free can theoretically corrupt reclaimed memory.
* Weak LPE concern is not separately awarded because the repeated-lifetime mutation is already counted.
* Structured stale-object leverage is not separately awarded. The shown stale operation is the second free itself, not a distinct post-reuse structured-field consumption path.
* Remote reachability is not established.
* Local unprivileged reachability is not established.
* No race penalty is applied. The supplied evidence describes ordered error-unwind paths, not a narrow timing race.
* No host-admin penalty is applied. Host-admin-equivalent privilege is plausible for explicit driver rebinding or device management, but it is not positively established as required for the complete vulnerable sequence.
* No rare-hardware penalty is applied. IPU6 support requires compatible Intel hardware, but the supplied evidence does not establish physical-only attacker access or a genuinely rare hardware prerequisite.

Repeated lifetime analysis:

* First release can end lifetime: yes. The commit explicitly states that `put_device()` and `auxiliary_device_uninit()` run the bus release callback, which frees `adev->pdata`.
* Exact same reference survives: yes. The local `pdata` pointer remains available after the release path returns.
* Second operation mutates lifetime state: yes. `kfree(pdata)` attempts a second free of the already released allocation.
* Concrete repeated release/refcount signal awarded: yes, +1.
* Paranoid repeated-refcount or free leverage awarded: yes, +1. The reason is the concrete second allocator free through potentially post-lifetime storage, not generic hypothetical heap reuse.
* FLOOR 5 applied: yes, for the conservative score.

3. Reachability analysis

The vulnerable paths are in Intel IPU6 isys and psys auxiliary-device initialization error handling. The first path is reached when MMU initialization fails after the auxiliary device has been initialized. The second path is reached when `ipu6_bus_add_device()` fails after auxiliary-device initialization.

The supplied patch does not establish that an ordinary local user can force either error condition. It also does not establish that host root or init-user-namespace administrative privilege is always required. Therefore, `HostAdminRequired=UNKNOWN` is more accurate than assuming either host administrator or unprivileged reachability.

The complete trigger appears tied to driver probe, initialization, reset, or device reinitialization behavior on systems using compatible IPU6 hardware. Explicit module loading, PCI driver rebinding, or fault injection would commonly involve elevated management privileges, but that deployment assumption is not sufficient to classify the requirement as proven host-admin-equivalent privilege.

No relevant namespace-scoped capability path is shown. The issue is not directly network reachable. No evidence establishes that a container, user namespace, or delegated media service can complete the MMU or auxiliary-device failure sequence. `NamespaceScopedPrivilege=UNKNOWN` is therefore appropriate.

4. Primitive and severity interpretation

The exact primitive is a concrete heap double free and equivalent real lifetime violation.

A. Ordinary stale cleanup dereference would be a stale pointer passed to cleanup code that immediately faults while reading stale state.

B. This issue is stronger than that constrained pattern. The release callback can free `adev->pdata`, the exact same `pdata` pointer remains live in the caller, and the caller then performs a second `kfree(pdata)`. The second operation actively performs a lifetime and allocator mutation through potentially freed storage.

The affected pdata allocation is associated with an active auxiliary-device initialization path, but the supplied evidence does not show attacker-controlled replacement contents, controlled slab reclaim, callback consumption after reuse, arbitrary read or write, or credential manipulation. It therefore remains `CLASS_B`, not `CLASS_A`.

The demonstrated practical consequence is kernel memory corruption with likely crash or DoS behavior. Privilege escalation is not demonstrated. The paranoid score preserves the unresolved security relevance of a concrete post-lifetime allocator mutation without claiming arbitrary kernel read/write or LPE.

`ImportantCandidate=YES` because the exact repeated free is concrete and post-lifetime corruption leverage remains unresolved. `AutoDowngradeAllowed=NO` because automatically treating this as an ordinary crash-only cleanup failure would discard the established second free through a potentially dangling reference.

Operationally, this should be handled as an actionable memory-corruption issue on systems with affected IPU6 hardware and driver paths. It requires manual assessment of actual driver exposure, initialization failure reachability, and allocator behavior in the target kernel configuration.

5. One-sentence report phrase

A double free in Intel IPU6 auxiliary-device initialization error handling can free pdata through the device release callback and then free the same pointer again, causing kernel heap corruption and potential denial of service.

6. Manual review recommendation

MANUAL CHECK REQUIRED

A concrete repeated lifetime mutation is established. The first release can free pdata and the exact same pointer is subsequently passed to `kfree()`, leaving unresolved post-lifetime allocator-corruption leverage even though controlled reclaim and privilege escalation are not demonstrated.

7. Call-site confidence

Call-site confidence: medium

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

Patch: media: ipu6: Do not free aux device pdata after init [ Upstream
Commit: faa1eb97f0e66bf122f44b62be6b323f86333e9f
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=faa1eb97f0e66bf122f44b62be6b323f86333e9f

Changed files:
  drivers/media/pci/intel/ipu6/ipu6.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=faa1eb97f0e66bf122f44b62be6b323f86333e9f

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

The original Linux kernel CVE announcement for CVE-2026-93070 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93070

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:H/UI:N/S:U/C:H/I:H/A:H
  The Best / paranoid CVSS score: 6.4

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: 5
  Paranoid ActionableScore: 6

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: YES
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).