[CVE-2026-98129][LOW] scsi: mpi3mr: Fix NULL pointer dereference in mpi3mr_sas_port_add() [ Upstream

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

CVE: CVE-2026-98129
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: scsi: mpi3mr: Fix NULL pointer dereference in mpi3mr_sas_port_add() [ Upstream
Commit: 5c50137ba11b6e20e7074303dae35ff58d5a0b6f
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5c50137ba11b6e20e7074303dae35ff58d5a0b6f
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98129
Analysis date: Fri, 25 Sep 2026 08:10:37 -0400
ActionableScore: 2
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-2026-98129 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98129

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-2026-98129	LOW	https://www.kernelcve.org/list/?q=CVE-2026-98129 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:N/I:N/A:H';**CWE-476;*CWE-401;CWE-703;BEST CVSS score: '4.1';DESCR 'A NULL pointer dereference can occur in mpi3mr_sas_port_add when sas_port_alloc_num fails during SAS port creation and returns NULL. The unchecked pointer is passed to sas_port_add and can cause a kernel Oops or panic. Triggering requires SAS expander discovery or port creation together with a memory allocation failure. For the CVSS the PR:H because reliable triggering normally requires administrator level control of SCSI device management rescan operations or the relevant SAS hardware topology. The issue is not network reachable. Impact is denial of service through a kernel crash. The separate sas_port leak on the sas_port_add failure path is a resource leak and does not provide evidence of memory corruption or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2)	YES	NULLPTR INIT LEAK UAF HARDWARE LINUS 	NO	NO	checked

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

ActionableScore=2
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=NO
ManualReview=NO
AutoDowngradeAllowed=YES

1. ActionableScore

* Raw conservative score: 2
* Conservative score: 2
* Raw paranoid score: 2
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate**::

2. Signal breakdown

* +1 Reliable kernel crash or strong DoS. Passing a NULL result from sas_port_alloc_num to sas_port_add can cause a kernel NULL pointer dereference, Oops, or panic.
* +1 Concrete persistent kernel resource leak. If sas_port_add fails after allocation, the allocated sas_port was not released before the error path.
* +0 No UAF. The patch does not show an object being freed while a stale reference remains in use.
* +0 No arbitrary write, controlled reclaim, type confusion, callback control, or attacker controlled post-free state is demonstrated.
* +0 No confidentiality or integrity impact is established. The NULL dereference and resource leak do not provide a disclosure or modification primitive.
* +0 No remote reachability is established. SAS port creation occurs in driver and SAS topology handling paths.
* +0 No local unprivileged trigger is established. The supplied patch does not show that an ordinary user can cause SAS expander discovery, port creation, and allocation failure.
* +0 No privilege penalty was applied. Host-admin-equivalent access may be relevant to device management or topology changes, but that requirement is not conclusively established by the supplied code.
* +0 No rare hardware penalty was applied. The code is driver specific, but the evidence does not prove a physical-only or unusually rare hardware attack prerequisite.
* +0 No additional availability point was awarded. The leak and the NULL dereference are separate defects, but no persistent host-wide resource exhaustion beyond the directly shown leaked sas_port is established.

3. Reachability analysis

The vulnerable function is in the mpi3mr SAS transport path and is reached while creating a SAS port for an expander-related device topology event. The immediate crash condition requires sas_port_alloc_num to fail due to allocation failure and then requires the error result to be passed to sas_port_add.

The supplied patch does not establish whether an ordinary local user, a namespace-scoped privileged user, or only a host administrator can drive the complete SAS discovery and port-addition sequence. Device rescan, controller management, SAS topology manipulation, and expander attachment may be privileged or hardware-mediated, but this cannot be treated as a proven host-admin requirement from the shown context alone.

No network-reachable path is shown. No namespace-scoped capability path is shown. No prior privileged setup, special boot option, sysctl, or attacker-controlled firmware path is established. The issue is not a race.

4. Primitive and severity interpretation

The exact primitive is an invalid NULL pointer dereference caused by unchecked memory-allocation failure. This is a crash-capable invalid-state bug, not a use-after-free, double-free, stale-object use, refcount mutation, or active-object lifetime violation.

The second defect is a concrete sas_port resource leak when sas_port_add fails. It is a normal error-path cleanup omission. The patch adds sas_port_free before entering out_fail. No second release of the same reference exists, so this is not a repeated-release or refcount corruption case.

PrimitiveClass is CLASS_C because the demonstrated behavior is kernel crash or DoS plus a limited resource leak. Controlled corruption, object replacement, arbitrary read or write, information disclosure, privilege escalation, and a security-boundary bypass are not supported by the patch. ImportantCandidate is NO because there is no unresolved meaningful corruption primitive beyond the crash and leak. AutoDowngradeAllowed is YES because the available evidence supports ordinary crash and resource-leak handling rather than an exploitable lifetime or ownership flaw.

5. One-sentence report phrase

An unchecked NULL return from sas_port_alloc_num can be passed to sas_port_add during mpi3mr SAS port creation, causing a kernel NULL pointer dereference and possible denial of service, while a separate sas_port_add failure path leaks the allocated SAS port object.

6. Manual review recommendation

NO MANUAL CHECK NEEDED

The patch establishes a NULL dereference and limited error-path resource leak without UAF, memory corruption, attacker-controlled data reuse, remote exposure, or a privilege-boundary bypass.

7. Call-site confidence

Call-site confidence: medium

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

Patch: scsi: mpi3mr: Fix NULL pointer dereference in mpi3mr_sas_port_add() [ Upstream
Commit: 5c50137ba11b6e20e7074303dae35ff58d5a0b6f
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5c50137ba11b6e20e7074303dae35ff58d5a0b6f

Changed files:
  drivers/scsi/mpi3mr/mpi3mr_transport.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=5c50137ba11b6e20e7074303dae35ff58d5a0b6f

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

The original Linux kernel CVE announcement for CVE-2026-98129 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98129

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: Not available
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 4.1

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: 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).