[CVE-2026-74526][LOW] scsi: mpi3mr: Fix potential deadlock in mpi3mr_fault_uevent_emit [ Upstream

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

CVE: CVE-2026-74526
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: scsi: mpi3mr: Fix potential deadlock in mpi3mr_fault_uevent_emit [ Upstream
Commit: df817b19dac7034416d18f14347010b3e9f5cf3d
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=df817b19dac7034416d18f14347010b3e9f5cf3d
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74526
Analysis date: Sat, 15 Aug 2026 10:01:07 -0400
ActionableScore: 2
ActionableScore lower bound: 1
Actionable bucket: Ordinary Moderate / Low-like. Not an Actionable Moderate candidate
Manual review required: NO

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-74526 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74526

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-2026-74526	LOW	CHECK WITH IMPACT FROM ORIG NN MODERATE	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-833;**CWE-400;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 'mpi3mr_fault_uevent_emit can run while the controller is in fault or reset handling and host I/O is already blocked. GFP_KERNEL allocations in this path can enter reclaim and wait on the same blocked I/O path, which may deadlock the fault reporting or reset flow. For the CVSS the PR:L is used in the paranoid view because a local user or service account may be able to create memory pressure and I/O load while the controller is already in a fault or reset state. Reliable triggering is still environment dependent and often requires an actual controller fault or administrative reset capability. The issue is not network reachable and does not provide a demonstrated memory corruption primitive. Impact is denial of service through stalled storage recovery or blocked I/O, with no direct evidence of information disclosure or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like. Not an Actionable Moderate candidate (with actual score 2)  SKIP CVE-2026-74526 UNKNOWN SKIP The Fixes patch not applied yet, so unlikely that actual: ec54b348f274fdd2bd32bbe74de6d62ae1a10a18 YES  NO NO unknown 	MAYBE	DEADLOCK SIMPLEFIX HARDWARE  DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_GUESSCVSS_AND_CIANNH	-	-	checked

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

ActionableScore=2
ActionableScoreLower=1

1. ActionableScore
* Conservative score: 1
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate / Low-like. Not an Actionable Moderate candidate**

2. Signal breakdown
* Firmware-mediated external influence: +1 in paranoid only. The path depends on controller fault or reset handling, so an external device or firmware fault can contribute, but this is not a normal remote attack surface.
* Reliable kernel crash / strong DoS: +1. The described failure mode is a deadlock in fault/reset reporting when reclaim waits on already blocked host I/O.
* Availability impact realistic: +1. A deadlock in a storage recovery path can block I/O and affect system availability beyond a simple warning.
* Important filesystem/storage path: +1. The affected driver is in the SCSI storage stack and the impact is blocked host I/O or stalled recovery.
* Hard or unreliable condition: -1. Triggering depends on fault/reset timing plus reclaim under blocked I/O.
* Rare/device-specific subsystem: -1. The issue is specific to mpi3mr controller hardware and its fault uevent path.
* Requires admin/root or fault precondition in typical deployments: effectively negative in conservative scoring. Reliable triggering usually requires controller reset/fault conditions or privileged device management, not ordinary user access.
* No memory corruption signal. The patch does not show UAF, OOB write, double free, type confusion, refcount takeover, arbitrary write, or stale callback.

3. Reachability analysis
This is not network reachable. A local unprivileged user may be able to create memory pressure or I/O pressure, but that alone is not enough for reliable triggering without an mpi3mr controller fault or reset path being active. In typical deployments, reset and direct controller management require administrative privileges, while the firmware fault condition is hardware or firmware mediated. Namespaces and containers do not materially lower the trigger requirement unless a container or service is delegated meaningful control over the storage device, which is uncommon.

4. Severity interpretation
This behaves like an ordinary Moderate or Low-like storage DoS, not an Important-class kernel vulnerability. The realistic impact is stalled storage recovery or blocked I/O due to reclaim recursion under GFP_KERNEL allocation. There is no demonstrated confidentiality impact, integrity impact, privilege escalation path, or memory corruption primitive. The paranoid score remains low because the worst supported interpretation is still a device-specific deadlock with difficult preconditions.

5. One-sentence report phrase
A GFP_KERNEL allocation in mpi3mr_fault_uevent_emit can enter reclaim while host I/O is already blocked during controller fault or reset handling, causing a storage recovery deadlock and denial of service.

6. Manual review recommendation
NO MANUAL CHECK NEEDED.
Reason: no memory corruption, no network reachability, no privilege escalation evidence, and practical triggering depends on device-specific fault/reset conditions.

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

Patch: scsi: mpi3mr: Fix potential deadlock in mpi3mr_fault_uevent_emit [ Upstream
Commit: df817b19dac7034416d18f14347010b3e9f5cf3d
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=df817b19dac7034416d18f14347010b3e9f5cf3d

Changed files:
  drivers/scsi/mpi3mr/mpi3mr_fw.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=df817b19dac7034416d18f14347010b3e9f5cf3d

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

The original Linux kernel CVE announcement for CVE-2026-74526 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74526

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: 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).