[CVE-2026-72007][LOW] pmdomain: imx: Fix i.MX8MP VC8000E power up sequence

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

CVE: CVE-2026-72007
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: pmdomain: imx: Fix i.MX8MP VC8000E power up sequence
Commit: 87af3ebc112fb3f06753794390daf0f665f151b4
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=87af3ebc112fb3f06753794390daf0f665f151b4
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72007
Analysis date: Sat, 15 Aug 2026 22:41:49 -0400
ActionableScore: 1
ActionableScore lower bound: 0
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
An incorrect i.MX8MP VC8000E power-up clock sequence can hit hardware errata ERR050531 and hang the VPU_NOC handshake, causing a local device or subsystem denial of service without evidence of memory corruption or privilege escalation.

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ABOUT THIS REPORT
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The original Linux kernel CVE announcement for CVE-2026-72007 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72007

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: LOW
Manual review required: NO

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-2026-72007	LOW	CHECK WITH IMPACT FROM ORIG NN MODERATE	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';CWE-696;CWE-703;CWE-754;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.7';DESCR 'The i.MX8MP VC8000E power domain sequence can hit a hardware erratum where VC8000E reset deassertion and the AXI clock edge have a timing conflict during power up or power cycling. This may cause the VPU_NOC power down handshake to hang, resulting in a device or subsystem availability problem rather than memory corruption. For the CVSS the PR:L is used in the paranoid case because a local user or service with access to the video encoder device may be able to cause runtime power cycling without full administrator privileges on some embedded systems. The issue is not network reachable and there is no UAF, OOB access, information leak, or privilege escalation primitive visible from the code change. Impact is denial of service limited to the affected media or power domain path.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1)	YES	INIT SIMPLEFIX LINUS  DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_GUESSCVSS_AND_CIANNH	YES	NO	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=1
ActionableScoreLower=0

## 1. ActionableScore

* Conservative score: 0
* Paranoid score: 1
* Final recommended bucket: **Ordinary Moderate / Low-like**

## 2. Signal breakdown

Triggered signals:

* Availability impact realistic: +1
  The erratum can cause a VPU_NOC power down handshake hang during VC8000E or VPUMIX power cycling.

Subtracting signals:

* Physical-only or rare hardware-only condition: -2
  The issue is specific to i.MX8MP VC8000E hardware behavior and errata ERR050531.
* Requires admin/root/CAP_* in typical deployments: -2 for conservative scoring
  Direct power-domain control and driver-level power sequencing are normally not exposed to ordinary users.

Paranoid-only consideration:

* Local unprivileged trigger: +1
  In some embedded deployments, a local user or media service with access to the video encoder device may indirectly cause runtime PM power cycling. This is plausible but configuration-dependent.

Not awarded:

* No generic memory corruption.
* No UAF, OOB write, double-free, refcount misuse, stale pointer, type confusion, or arbitrary write.
* No privilege escalation plausible.
* No network reachability.
* No confidentiality or integrity impact.
* No firmware-mediated external influence in the security sense.

## 3. Reachability analysis

The affected path is the i.MX8MP VC8000E power-domain power-up sequence. In typical deployments, triggering it requires use of the affected media hardware or power-management path, often through privileged driver/runtime PM activity. A less privileged local trigger is possible only if userspace has access to the video encoder device and can cause repeated runtime suspend/resume or power cycling. Namespaces do not materially reduce the privilege requirement unless the device node is deliberately exposed into a container. The path is not remotely reachable and applies only to systems using this specific NXP i.MX8MP hardware block.

Call-site confidence: high, because the relevant power-on function and domain data flag are shown directly in the patch.

## 4. Severity interpretation

This behaves like a hardware erratum reliability fix with local availability impact, not like an Important-class kernel vulnerability. The realistic impact is a device or subsystem hang during VC8000E power cycling. There is no evidence of memory corruption, privilege escalation, sensitive data exposure, or cross-boundary security bypass. The paranoid score only accounts for the possibility that local non-root media access can trigger repeated runtime PM transitions.

## 5. One-sentence report phrase

An incorrect i.MX8MP VC8000E power-up clock sequence can hit hardware errata ERR050531 and hang the VPU_NOC handshake, causing a local device or subsystem denial of service without evidence of memory corruption or privilege escalation.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

This can be auto-closed or handled as low-priority reliability unless the evaluated product exposes VC8000E power cycling to untrusted local users or containers.

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UPSTREAM PATCH SUMMARY
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Patch: pmdomain: imx: Fix i.MX8MP VC8000E power up sequence
Commit: 87af3ebc112fb3f06753794390daf0f665f151b4
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=87af3ebc112fb3f06753794390daf0f665f151b4

Commit description:

Per errata[1]:
ERR050531: VPU_NOC power down handshake may hang during VC8000E/VPUMIX
power up/down cycling.
Description: VC8000E reset de-assertion edge and AXI clock may have a
timing issue.
Workaround: Set bit2 (vc8000e_clk_en) of BLK_CLK_EN_CSR to 0 to gate off
both AXI clock and VC8000E clock sent to VC8000E and AXI clock sent to
VPU_NOC m_v_2 interface during VC8000E power up(VC8000E reset is
de-asserted by HW)

Add a bool variable is_errata_err050531 in
'struct imx8m_blk_ctrl_domain_data' to represent whether the workaround
is needed. If is_errata_err050531 is true, first clear the clk before
powering up gpc, then enable the clk after powering up gpc.

[1] https://www.nxp.com/webapp/Download?colCode=IMX8MP_1P33A

Fixes: a1a5f15 ("soc: imx: imx8m-blk-ctrl: add i.MX8MP VPU blk ctrl")
Cc: stable@vger.kernel.org
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Ulf Hansson <ulfh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/pmdomain/imx/imx8m-blk-ctrl.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=87af3ebc112fb3f06753794390daf0f665f151b4

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

The original Linux kernel CVE announcement for CVE-2026-72007 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72007

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:L
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 4.7

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: 0
  Paranoid ActionableScore: 1

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: LOW
KPANIC detected for this report: NO
Published priority for this report (same as in Subject): LOW

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).