* [CVE-2026-98931][LOW] mtd: spinand: fix NULL pointer dereference with no ECC engine [ Upstream
@ 2026-10-26 19:23 21% AL-KERNEL
0 siblings, 0 replies; 1+ results
From: AL-KERNEL @ 2026-10-26 19:23 UTC (permalink / raw)
To: kernel-cve
CVE: CVE-2026-98931
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: mtd: spinand: fix NULL pointer dereference with no ECC engine [ Upstream
Commit: 77c449c9c946fc420008dc55cd30f53749c915e4
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=77c449c9c946fc420008dc55cd30f53749c915e4
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98931
Analysis date: Mon, 26 Oct 2026 15:23:37 -0400
ActionableScore: 1
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO
Summary:
A valid no-ECC SPI-NAND configuration causes a deterministic NULL dereference during device probing, yielding an Oops and failed device initialization without a demonstrated corruption or boundary-bypass primitive.
======================================================================
ABOUT THIS REPORT
======================================================================
The original Linux kernel CVE announcement for CVE-2026-98931 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98931
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-2026-98931 LOW https://www.kernelcve.org/list/?q=CVE-2026-98931 CHECK WITH IMPACT FROM ORIG NN MODERATE | AEGIS IMPACT LOW AEGIS_AS=0 LEGACY=LOW RESULT=SAME (final reconciliation agrees; 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-476;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.5';DESCR 'SPI NAND dereferences nand ecc engine during device probing even though nanddev_get_ecc_engine may validly leave the pointer NULL when nand-no-ecc-engine is configured. The demonstrated primitive is a NULL pointer dereference that causes an oops and prevents successful device initialization. It does not provide an OOB access, UAF, information leak, or controlled write. For the CVSS the PR:L paranoid case applies only if a restricted local service can control DT overlays or device reprobe. Normal systems require administrative control over the hardware description and therefore fit PR:H. Availability may become high with panic_on_oops or when the affected NAND device is essential for system operation. Automated impact decision path. The original SimpleNet classifier selected MODERATE. 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 ActionableScore thresholds stage MODERATE 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 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3. The independent weaker Aegis shadow evaluated CVSS 2.3 and ActionableScore 0 with primitive class CLASS_C and manual review REQUIRED. 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 OOB NULLPTR SIMPLEFIX HARDWARE LINUS TEST DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 - - checked
======================================================================
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 base 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 fault/device-probe DoS: `nand->ecc.engine` can validly remain NULL, but three SPI-NAND paths dereference it; the commit states probing immediately oopses.
* No additional availability point: failed initialization and the Oops are the same consequence. Host-wide panic requires an additional configuration such as `panic_on_oops`.
* No privilege penalty: DT control and reprobe normally suggest administrative setup, but the supplied evidence does not conclusively establish the complete trigger actor, so host-admin privilege remains unknown.
* No UAF, OOB access, heap overwrite, stale lifetime operation, controlled write, disclosure, or authorization bypass is shown.
* B5-R and B3-PENDING do not apply: there is no write or shared-backing modification.
3. Reachability analysis
The fault requires an SPI-NAND device described with `nand-no-ecc-engine` and execution of its probe or I/O setup paths. Ordinary users cannot normally modify the device tree or instantiate this hardware path, but the patch does not establish whether overlays or reprobe are exposed to a delegated service. Thus below-host-admin reachability is unproven, as is an absolute host-admin requirement. No namespace capability path is involved, and no race is required.
4. Primitive and severity reading
The exact primitive is a deterministic NULL-pointer dereference of `nand->ecc.engine`, not memory corruption or a lifetime violation. The affected state is fixed device configuration, and the shown effect is an immediate probe-time Oops preventing device initialization. A host panic or broader outage is conditional rather than proven. This is CLASS_C crash/invalid-state behavior, with no material exploit leverage past the fault; therefore it is not an Important candidate and may be auto-downgraded.
5. One-sentence report phrase
A valid no-ECC SPI-NAND configuration causes a deterministic NULL dereference during device probing, yielding an Oops and failed device initialization without a demonstrated corruption or boundary-bypass primitive.
6. Manual review advice
NO MANUAL CHECK NEEDED
The patch fully explains a constrained NULL dereference with no unresolved exploit primitive.
7. Call-site confidence
Call-site confidence: high
======================================================================
UPSTREAM PATCH SUMMARY
======================================================================
Patch: mtd: spinand: fix NULL pointer dereference with no ECC engine [ Upstream
Commit: 77c449c9c946fc420008dc55cd30f53749c915e4
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=77c449c9c946fc420008dc55cd30f53749c915e4
Changed files:
drivers/mtd/nand/spi/core.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=77c449c9c946fc420008dc55cd30f53749c915e4
======================================================================
DETAILED REPORT METHODOLOGY
======================================================================
The original Linux kernel CVE announcement for CVE-2026-98931 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98931
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:L/PR:H/UI:N/S:U/C:N/I:N/A:L
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 [email protected] (and both
send reply to CVE record itself too and see "reply" button below for howto reply).
^ permalink raw reply [relevance 21%]
Results 1-1 of 1 | reverse | sort options + mbox downloads above
-- links below jump to the message on this page --
2026-10-26 19:23 21% [CVE-2026-98931][LOW] mtd: spinand: fix NULL pointer dereference with no ECC engine [ Upstream AL-KERNEL
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox