[CVE-2026-98410][LOW] watchdog: da9063: fix suspend/resume handling of HW_RUNNING watchdog

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

CVE: CVE-2026-98410
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: watchdog: da9063: fix suspend/resume handling of HW_RUNNING watchdog
Commit: 95adc37f47cdf5a5285f7163b24243680af510be
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=95adc37f47cdf5a5285f7163b24243680af510be
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98410
Analysis date: Wed, 14 Oct 2026 23:23:51 -0400
ActionableScore: 1
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-98410 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98410

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.

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

CVE-2026-98410	LOW	https://www.kernelcve.org/list/?q=CVE-2026-98410 CHECK WITH IMPACT FROM ORIG NN LOW | AEGIS IMPACT LOW AEGIS_AS=0 LEGACY=LOW RESULT=SAME (legacy and Aegis reconciliation agree; DECISION: both 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-754;CWE-703;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.5';DESCR 'The DA9063 suspend callback checked only WDOG_ACTIVE and ignored WDOG_HW_RUNNING. When the driver left the hardware watchdog running but userspace had never opened the watchdog device, suspend did not stop the timer and a sufficiently long suspend could cause an unexpected system reset. For the CVSS the PR:L used by the paranoid score reflects systems where an active local user or a restricted service can request suspend through logind or a similar power management interface. The issue is not directly network reachable and requires affected DA9063 hardware, software managed suspend, and a hardware running watchdog. Impact is denial of service through a system reset. There is no supported memory corruption, information disclosure, integrity impact, or privilege escalation primitive. Automated impact decision path. The original SimpleNet classifier selected LOW. The primary LLM estimated paranoid CVSS 5.5 and the production ActionableScore returned 1 with recommendation Ordinary Moderate. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were CVSS and initial triage stage LOW to MODERATE_KPANIC because the CVSS score, vector or bug class threshold rule was applied. ActionableScore thresholds stage MODERATE_KPANIC to LOW because the ActionableScore threshold rule was applied. The legacy KP specialist has no review artifact for this run. The legacy FD or DH downgrade specialist has no review artifact for this run. Exact triggered rule markers were INCREASED_FROM_LOW_BASED_ON_HIGHCVSSSCORE and DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 and DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3. The independent weaker Aegis shadow evaluated CVSS 4.2 and ActionableScore 0 with primitive class CLASS_C and manual review NO. Its independently reconciled impact was LOW. The shadow agreed with the final production impact and aggregation did not change that impact. The final reported impact is LOW.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 1)	MAYBE	SIMPLEFIX HARDWARE LINUS  INCREASED_FROM_LOW_BASED_ON_HIGHCVSSSCORE DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	-	-	checked

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

ActionableScore=1
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=NO
AutoDowngradeAllowed=YES
RequiresHostUID0=UNKNOWN
AuthorizationDecisionBypass=NO
ProtectedResourceImpact=NONE
B4PendingReview=NO
B4PendingConfirmed=NO

1. ActionableScore

* Raw conservative score: 1
* Conservative score: 1
* Raw paranoid score: 1
* Paranoid score: 1
* No floor or cap was applied.
* Final recommended bucket: **Ordinary Moderate**::

2. Signal breakdown

* +1 Reliable strong DoS. An active hardware watchdog can continue counting during suspend and reset the entire system.
* No additional availability point. The unexpected reset is the same DoS consequence.
* No corruption point. The patch establishes an incorrect watchdog-state check, not a UAF, OOB access, overwrite, or lifetime violation.
* No local-unprivileged bonus. Some power-management policies may permit a logged-in user to request suspend, but complete below-host-admin reachability is not established.
* No privilege penalty. Host-administrator privilege is also not positively established.
* No hardware penalty. DA9063 hardware is required, but the supplied evidence does not establish that it is sufficiently rare for a scoring reduction.
* No authorization signal. The change checks runtime watchdog state and does not restore an access-control decision.
* No B5-R or B3-PENDING signal. There is no heap OOB write, retry accumulation, or shared-backing write.

3. Reachability analysis

The affected system must contain a DA9063 watchdog, enable software suspend handling through `use_sw_pm`, and have the hardware watchdog running while `WDOG_ACTIVE` remains clear because userspace never opened the watchdog device. A suspend interval exceeding the watchdog timeout can then reset the host.

The actor allowed to request host suspend depends on system power-management policy. The supplied evidence does not prove either ordinary-user reachability or a host-admin-only requirement, so `HostAdminRequired` and `RequiresHostUID0` remain unknown. System suspend is host-global and is not an attacker-created namespace operation, so the complete trigger is not namespace-scoped. No race or narrow timing window is required after the vulnerable state exists.

4. Primitive and severity interpretation

The exact defect is an incomplete state check: `watchdog_active()` observes `WDOG_ACTIVE` but misses a watchdog represented only by `WDOG_HW_RUNNING`. The suspend callback consequently fails to stop the active hardware timer.

This is `CLASS_C` invalid-state and DoS behavior. It is not stale storage, an active-object UAF, a repeated release, memory corruption, or an authorization bypass. The demonstrated consequence is an unexpected system reset. No confidentiality, integrity, privilege-escalation, or independently useful exploitation primitive is supported.

`ImportantCandidate=NO` because the patch establishes only configuration-dependent availability loss. `AutoDowngradeAllowed=YES` because no unresolved corruption, ownership, lifetime, or security-boundary primitive remains.

5. One-sentence report phrase

The DA9063 suspend callback ignored a hardware-running watchdog when WDOG_ACTIVE was clear, allowing the watchdog to reset an affected system during a sufficiently long suspend.

6. Manual review recommendation

NO MANUAL CHECK NEEDED

The issue is a hardware-specific state-handling defect with reset-only impact and no established memory-corruption or security-boundary primitive.

7. Call-site confidence

Call-site confidence: high

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

Patch: watchdog: da9063: fix suspend/resume handling of HW_RUNNING watchdog
Commit: 95adc37f47cdf5a5285f7163b24243680af510be
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=95adc37f47cdf5a5285f7163b24243680af510be

Commit description:

da9063_wdt_suspend() and da9063_wdt_resume() only check watchdog_active(),
when the watchdog is left running by the driver sets
WDOG_HW_RUNNING in da9063_wdt_probe() but userspace never opens the
device, so WDOG_ACTIVE remains cleared, the wdt_disable() will not be
executed in da9063_wdt_suspend. In this case, the suspend callback is
a no-op and the watchdog keeps counting during system suspend,
leading to an unexpected system reset.
Check WDOG_HW_RUNNING and wdd，can fix this issue.

Fixes: a7ceca4 ("watchdog: da9063: optionally disable watchdog during suspend")
Cc: stable@vger.kernel.org
Signed-off-by: Li Jun <lijun01@kylinos.cn>
Link: https://patch.msgid.link/20260917013710.2754679-1-lijun01@kylinos.cn
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/watchdog/da9063_wdt.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=95adc37f47cdf5a5285f7163b24243680af510be

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

The original Linux kernel CVE announcement for CVE-2026-98410 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98410

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: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: unknown
  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).