[CVE-2026-93199][LOW] i3c: master: Do not treat master device as a duplicate target [ Upstream

[CVE-2026-93199][LOW] i3c: master: Do not treat master device as a duplicate target [ Upstream

[AL-KERNEL]

CVE: CVE-2026-93199
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: i3c: master: Do not treat master device as a duplicate target [ Upstream
Commit: d0cc00957292e353ad46039034cd8f82fc4f8057
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d0cc00957292e353ad46039034cd8f82fc4f8057
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93199
Analysis date: Fri, 18 Sep 2026 07:48:48 -0400
ActionableScore: 2
ActionableScore lower bound: 1
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-2026-93199 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93199

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-2026-93199	LOW	https://www.kernelcve.org/list/?q=CVE-2026-93199 CHECK WITH IMPACT FROM ORIG NN LOW	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L';CWE-697;CWE-754;CWE-665;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '2.4';DESCR 'The I3C duplicate device search can incorrectly match the controller device itself when a target device has the same PID as master this. This may cause a valid I3C target to be treated as a duplicate and can break device discovery or registration on the affected bus. For the CVSS the PR:N is used for the paranoid physical access scenario because a malicious or misconfigured I3C target device does not need an existing local user account on the victim. The issue is not network reachable and is limited to local hardware or bus management conditions. Impact is denial of service or device availability degradation only.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2) 	MAYBE	SIMPLEFIX HARDWARE 	-	-	checked

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

ActionableScore=2
ActionableScoreLower=1
PrimitiveClass=NONE
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=NO
AutoDowngradeAllowed=YES

1. ActionableScore

* Raw conservative score: 1
* Conservative score: 1. No floor or cap applied.
* Raw paranoid score: 2
* Paranoid score: 2. No floor or cap applied.
* Final recommended bucket: **Ordinary Moderate**::

2. Signal breakdown

Positive conservative signals:

* +1 limited device availability impact. The duplicate PID search may incorrectly classify the I3C controller itself as a duplicate target device, which can break target discovery or registration on the affected bus.

Positive paranoid signals:

* +1 limited device availability impact. Same as conservative.
* +1 physical or bus mediated external influence. A malicious or misconfigured I3C target device with a conflicting PID could plausibly influence the condition, but this is not direct network reachability.

Non-awarded signals:

* No UAF or stale lifetime primitive is established.
* No OOB access, arbitrary write, controlled corruption, refcount mutation, or double release is established.
* No reliable kernel crash or host-wide DoS is shown.
* No confidentiality or integrity impact is supported.
* No authorization or security-boundary bypass is established.
* No remote network reachability is established.
* No race, RCU, KVM, filesystem COW, or shared-page ownership issue is involved.

Negative signals:

* No explicit negative point was applied. The hardware or physical nature limits practical exposure, but the final score is already low and no additional penalty is needed.

3. Reachability analysis

The most plausible trigger is during I3C bus enumeration or target device registration when a real target device has the same PID as the controller object represented by master this. A host administrator or kernel-managed bus setup may encounter the bug during normal device discovery. A paranoid scenario involves a malicious or misconfigured physical I3C target device on the bus, but that is still local hardware or bus-level influence, not network-triggered exploitation.

Host-admin-equivalent privilege is not positively established for every possible scenario, because a physical device could contribute the conflicting PID without a local user account. However, below-host-admin software reachability is also not established. Therefore HostAdminRequired is UNKNOWN. NamespaceScopedPrivilege is NO because there is no namespace-scoped capability path involved. No prior network exposure exists. Special I3C hardware or bus presence is required.

4. Primitive and severity interpretation

The exact primitive is an object identity comparison logic bug: i3c_master_search_i3c_dev_duplicate can match master this even though the controller is not a target device. This can cause incorrect duplicate detection and device registration or discovery failure.

PrimitiveClass is NONE because there is no meaningful kernel memory corruption, lifetime violation, ownership violation, authorization bypass, or active security primitive. The demonstrated consequence is limited device availability degradation. Stronger consequences such as privilege escalation, information disclosure, host-wide crash, or arbitrary kernel state corruption are not supported by the patch.

ImportantCandidate is NO because the issue is a constrained logic bug with low security leverage. AutoDowngradeAllowed is YES because no unresolved corruption or security-boundary primitive remains.

5. One-sentence report phrase

An I3C duplicate PID check could incorrectly match the controller itself as a duplicate target, causing device discovery or registration failure on the affected bus without evidence of memory corruption, privilege escalation, or network reachability.

6. Manual review recommendation

NO MANUAL CHECK NEEDED

Reason: the patch shows a narrow logic correction with only limited I3C bus availability impact and no established corruption, UAF, boundary bypass, or remote attack surface.

7. Call-site confidence

Call-site confidence: medium

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

Patch: i3c: master: Do not treat master device as a duplicate target [ Upstream
Commit: d0cc00957292e353ad46039034cd8f82fc4f8057
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d0cc00957292e353ad46039034cd8f82fc4f8057

Changed files:
  drivers/i3c/master.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=d0cc00957292e353ad46039034cd8f82fc4f8057

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

The original Linux kernel CVE announcement for CVE-2026-93199 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93199

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:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
  The Best / paranoid CVSS score: 2.4

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: 1
  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).