[CVE-2026-53340][LOW] i2c: imx: fix clock and pinctrl state inconsistency in runtime PM

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

CVE: CVE-2026-53340
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: i2c: imx: fix clock and pinctrl state inconsistency in runtime PM
Commit: 9fa82cf393bafc7bd7ca15c1d5cbd5b57ab9de1d
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9fa82cf393bafc7bd7ca15c1d5cbd5b57ab9de1d
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53340
Analysis date: Wed, 01 Jul 2026 09:52:58 -0400
ActionableScore: 2
ActionableScore lower bound: 0
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
An i2c-imx runtime PM ordering bug can leave the I2C clock disabled after a pinctrl sleep-state failure, causing a later hardware access to crash the system on affected i.MX platforms.

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

The original Linux kernel CVE announcement for CVE-2026-53340 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53340

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-2026-53340	LOW	CHECK	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-703;CWE-754;CWE-404;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '4.7';DESCR 'The i2c imx runtime PM path can leave the controller in an inconsistent state when runtime suspend disables the I2C clock before selecting the pinctrl sleep state. If pinctrl_pm_select_sleep_state() fails, suspend is aborted but the clock may remain disabled, and a later hardware access can crash the system. For the CVSS the PR:L is used in the paranoid score because a local user or service with access to the affected I2C device may indirectly trigger runtime PM transitions, even though reliable reproduction also depends on a pinctrl failure or platform configuration issue. The issue is not network reachable and is specific to affected i.MX platforms and runtime PM behavior. Impact is denial of service via system crash only, with no evidence of memory corruption, information disclosure, or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1)  SKIP CVE-2026-53340  SKIP The Fixes patch not applied yet, so unlikely that actual: 576eba03c99435380d155e5f71d5d7603b9178f6 YES  NO NO unknown 	MAYBE	DANGER USB SIMPLEFIX HARDWARE LINUS  DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	-	-	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=2
ActionableScoreLower=0

## 1. ActionableScore

* Conservative score: 0
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate / Low-like**

## 2. Signal breakdown

Conservative signals:

* Reliable kernel crash / strong DoS: +1
  The commit explicitly says the inconsistent runtime PM state can cause a system crash when I2C hardware is later accessed.
* Hard or special condition required: -1
  Triggering requires `pinctrl_pm_select_sleep_state()` or `clk_enable()` failure during runtime PM transitions, which is platform and configuration dependent.
* No memory corruption signal: +0
  The patch fixes ordering and rollback of clock and pinctrl state. It does not show UAF, OOB, double free, stale pointer reuse, arbitrary write, or type confusion.
* No confidentiality or integrity impact: +0
  The observed impact is crash only.

Paranoid additional signals:

* Local unprivileged trigger: +1
  In some deployments, a local user or service with access to an I2C client device may indirectly cause runtime PM suspend and resume activity.
* Availability impact realistic: +1
  If the platform enters the bad state, the resulting crash is system-wide rather than limited to a single device operation.

## 3. Reachability analysis

This is not network reachable. The affected path is the runtime PM suspend and resume logic of the i.MX I2C controller driver. Realistic triggering requires an affected i.MX platform, runtime PM activity, and a pinctrl or clock failure at the wrong point. Typical direct control over pinctrl and device power state is privileged or mediated by kernel PM policy, but paranoid scoring allows PR:L because local device access may indirectly drive runtime PM transitions. Containers and namespaces generally do not make this broadly reachable unless the affected I2C device is explicitly exposed.

## 4. Severity interpretation

This behaves like an ordinary Moderate or Low-like platform-specific DoS. The theoretical impact is a kernel or system crash, but there is no evidence of memory corruption, privilege escalation, information disclosure, or persistent data integrity damage. The bug is an error-handling and state-consistency issue in a hardware-specific driver path, not a generic kernel exploitation primitive.

## 5. One-sentence report phrase

An i2c-imx runtime PM ordering bug can leave the I2C clock disabled after a pinctrl sleep-state failure, causing a later hardware access to crash the system on affected i.MX platforms.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

Reason: no memory corruption, no network reachability, no privilege escalation path, and only platform-specific DoS impact under special runtime PM failure conditions.

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

Patch: i2c: imx: fix clock and pinctrl state inconsistency in runtime PM
Commit: 9fa82cf393bafc7bd7ca15c1d5cbd5b57ab9de1d
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9fa82cf393bafc7bd7ca15c1d5cbd5b57ab9de1d

Commit description:

In i2c_imx_runtime_suspend(), the clock is disabled before switching
the pinctrl state to sleep. If pinctrl_pm_select_sleep_state() fails,
the runtime suspend is aborted but the clock remains disabled, causing
a system crash when the hardware is subsequently accessed.

Fix this by switching the pinctrl state before disabling the clock so
that a pinctrl failure leaves the clock enabled and the hardware
accessible.

In i2c_imx_runtime_resume(), restore the pinctrl state back to sleep
if clk_enable() fails to keep the consistent.

Fixes: 576eba0 ("i2c: imx: switch different pinctrl state in different system power status")
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Cc: <stable@vger.kernel.org> # v6.14+
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260521065038.2954998-1-carlos.song@oss.nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/i2c/busses/i2c-imx.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=9fa82cf393bafc7bd7ca15c1d5cbd5b57ab9de1d

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

The original Linux kernel CVE announcement for CVE-2026-53340 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53340

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: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: 2

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).