[CVE-2026-98202][LOW] Input: synaptics-rmi4 - fix GPF in suspend and resume when unbound

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

CVE: CVE-2026-98202
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: Input: synaptics-rmi4 - fix GPF in suspend and resume when unbound
Commit: 7a3d7c68aa36f68e2a4824da4782c0e5d7c4eba4
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7a3d7c68aa36f68e2a4824da4782c0e5d7c4eba4
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98202
Analysis date: Fri, 09 Oct 2026 04:03:09 -0400
ActionableScore: 1
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-98202 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98202

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
======================================================================

CVE-2026-98202	LOW	https://www.kernelcve.org/list/?q=CVE-2026-98202 CHECK WITH IMPACT FROM ORIG NN MODERATE | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=0 LEGACY=LOW RESULT=DIFF TEMP_DISTANCE_MERGE_SKIP=AEGIS_NO_POSITIVE_SEVERITY_EVIDENCE (independent Legacy and Aegis differ; FINAL: LOW, Aegis: MODERATE_KPANIC)	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-476;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: '4.7';DESCR 'A NULL pointer dereference in the Synaptics RMI4 power management path occurs when rmi_driver_suspend or rmi_driver_resume is invoked for an RMI device whose physical driver did not bind or complete probe. In this state dev_get_drvdata returns NULL and the following IRQ control path attempts to access data enabled_mutex, resulting in a General Protection Fault and potentially a kernel crash during system suspend or resume. For the CVSS the PR:L value is used for the paranoid score because an authorized local desktop user may be able to request system suspend through a power management service, although reliable triggering still requires a specific unbound RMI device state. The issue is not network reachable. Impact is limited to local denial of service because the observed primitive is a NULL dereference and there is no UAF, OOB access, information leak, or controlled write supporting confidentiality, integrity, or privilege escalation impact.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 1)	MAYBE	DANGER NULLPTR INIT SIMPLEFIX HARDWARE LINUS SYZBOT  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
======================================================================

ActionableScore=1
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=NO
AutoDowngradeAllowed=YES

1. ActionableScore

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

2. Signal breakdown

* +1 Reliable kernel crash / strong DoS. The NULL driver-data pointer reaches IRQ handling, which accesses `data->enabled_mutex` and produces a General Protection Fault.
* +0 Weak corruption concern. This is a NULL-pointer dereference with no useful post-lifetime or overwrite primitive.
* No local-unprivileged bonus. A desktop user may be able to request suspend, but the complete sequence creating or retaining an unbound RMI device is not established as attacker-controlled.
* No privilege penalty. Host-admin-equivalent privilege is not positively established.
* No race penalty. The defect is a deterministic invalid-state path, not a timing race.
* No hardware penalty. RMI hardware is relevant, but the evidence does not establish a rare or physical-only security prerequisite warranting subtraction.
* No extra Availability point. The same GPF or kernel crash is already counted.
* No C/I, UAF, OOB, controlled write, disclosure, reclaim, repeated release, authorization bypass, or privilege-escalation signal is established.
* B5-R does not apply. There is no heap OOB write, retry-accumulated index, corrupted descriptor, or later consumption of OOB-corrupted state.

3. Reachability analysis

The vulnerable callbacks run during system suspend or resume when an I2C or SPI transport is operational but the physical RMI driver did not bind or complete probe. Who can create this unbound state and initiate the complete PM sequence is unresolved, so `HostAdminRequired=UNKNOWN`.

A locally authorized desktop user might request suspend through a power-management service, but that does not prove control over the prerequisite driver state. The path is not namespace-scoped, not network-reachable, and does not involve a repeatable attacker-controlled race. An RMI transport or equivalent test setup must exist, but rarity is not established.

4. Primitive and severity interpretation

The exact primitive is a NULL-pointer dereference while attempting to use an absent RMI driver-data object. It is neither fixed stale storage nor an active structured-object UAF because no object is shown to have been freed. No repeated release or refcount mutation exists.

The demonstrated consequence is a GPF and possible kernel crash during suspend or resume. No useful primitive remains after excluding the crash. Speculative confidentiality, integrity, arbitrary write, or privilege-escalation consequences are unsupported.

This is `CLASS_C`, not Class B or Class A. `ImportantCandidate=NO` because there is no unresolved corruption or security-boundary primitive. `AutoDowngradeAllowed=YES` because the evidence supports a constrained crash-only invalid-state bug.

5. One-sentence report phrase

An unbound Synaptics RMI4 device can leave driver data NULL during system suspend or resume, causing a General Protection Fault and local denial of service without an established memory-corruption or privilege-escalation primitive.

6. Manual review recommendation

NO MANUAL CHECK NEEDED

The issue is a constrained NULL dereference with crash-only impact, uncertain attacker control, and no UAF, OOB write, retry-accumulated corruption, authorization bypass, or network exposure.

7. Call-site confidence

Call-site confidence: high

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

Patch: Input: synaptics-rmi4 - fix GPF in suspend and resume when unbound
Commit: 7a3d7c68aa36f68e2a4824da4782c0e5d7c4eba4
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7a3d7c68aa36f68e2a4824da4782c0e5d7c4eba4

Commit description:

Transport drivers (such as rmi_i2c and rmi_spi) invoke
rmi_driver_suspend() and rmi_driver_resume() on their child rmi_dev
device during system power management events. However, transport drivers
are fully registered and operational even if the physical RMI driver
failed to bind or probe the rmi_dev device.

When rmi_driver_suspend() or rmi_driver_resume() is called on an unbound
rmi_dev, dev_get_drvdata() returns NULL. Calling rmi_disable_irq() or
rmi_enable_irq() without driver data attached causes a NULL pointer
dereference and General Protection Fault when attempting to lock
data->enabled_mutex.

Fix this by checking if driver data is attached to rmi_dev in
rmi_driver_suspend() and rmi_driver_resume(), exiting early if
no driver data is present.

Fixes: 2b6a321 ("Input: synaptics-rmi4 - add support for Synaptics RMI4 devices")
Reported-by: syzbot+09103639e39c989e3ed3@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=09103639e39c989e3ed3
Cc: stable@vger.kernel.org
Assisted-by: LLM
Link: https://patch.msgid.link/anQe8UiyUR4x0flD@google.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/input/rmi4/rmi_driver.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=7a3d7c68aa36f68e2a4824da4782c0e5d7c4eba4

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

The original Linux kernel CVE announcement for CVE-2026-98202 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98202

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: 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).