[CVE-2026-89845][MODERATE REGULAR] scsi: qla2xxx: Avoid req_q_map double-read in qla2x00_error_entry()

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

CVE: CVE-2026-89845
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: scsi: qla2xxx: Avoid req_q_map double-read in qla2x00_error_entry()
Commit: c845f2597787ef70159a32566669e308b2807a56
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c845f2597787ef70159a32566669e308b2807a56
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89845
Analysis date: Wed, 16 Sep 2026 15:33:38 -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-2026-89845 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89845

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: MODERATE REGULAR
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-2026-89845	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-89845 CHECK WITH IMPACT FROM ORIG NN MODERATE	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H';CWE-362;CWE-367;**CWE-476;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.3';DESCR 'A race in qla2x00_error_entry() can occur because ha req_q_map is read once for validation and read again later for assignment. During request queue teardown the same map slot can be cleared while the response queue interrupt path is still active, so the second read may return NULL and the request queue pointer can then be dereferenced. This can crash the kernel through a NULL-pointer dereference in the qla2xxx SCSI driver. For the CVSS the PR:N is used in the paranoid adjacent scenario because a malicious or compromised Fibre Channel fabric or target endpoint may not need a local account on the victim, although reliable triggering still depends on a teardown or reset timing window. The issue is not Internet reachable and is limited to systems using affected QLogic Fibre Channel hardware and exposed SAN connectivity. Impact is denial of service only based on the visible primitive.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2)	YES	NULLPTR SIMPLEFIX HARDWARE LINUS PACKET  DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH	NO	NO	checked

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

ActionableScore=2
ActionableScoreLower=1
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=RECOMMENDED
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

Conservative signals:

* +1 Concrete invalid-state dereference path. `qla2x00_error_entry()` can observe a non-NULL `req_q_map[que]` in the first read, then read NULL into `req` on the second read.
* +1 Reliable kernel crash / strong DoS. The resulting `req == NULL` is dereferenced in interrupt-driven qla2xxx error handling.
* -1 Hard timing / teardown race. The failure requires `req_q_map[que]` to be cleared between two close reads during queue teardown while the response-queue interrupt path remains active.

Paranoid additional signal:

* +1 Firmware or fabric mediated external influence. The vulnerable path processes bad response packets from a QLogic Fibre Channel storage environment, so a malicious or compromised SAN-side endpoint may contribute to trigger conditions, but this is not direct Internet reachability.

Important non-awarded signals:

* RealUAF not awarded. The supplied evidence establishes a NULL dereference after a double-read race, not a stale non-NULL pointer use after object lifetime ended.
* Controlled reclaim not demonstrated.
* Arbitrary write not demonstrated.
* Confidentiality and integrity impact not awarded.
* Remote network reachability not awarded. Fibre Channel or SAN adjacency is materially different from ordinary remote TCP/IP reachability.
* Extra Availability not awarded because the kernel crash is already counted once.
* Concrete repeated release/refcount signal not awarded. No first lifetime-ending release followed by a second put/release/refcount mutation on the same dangling reference is established.
* FLOOR 5 not applied because there is no UAF, no repeated lifetime mutation, and no meaningful exploitation leverage beyond crash.

3. Reachability analysis

The directly visible trigger is in the qla2xxx SCSI driver interrupt/error path while a request queue is being torn down. Reliable local triggering likely involves device reset, queue teardown, driver recovery, or similar host-side management activity, but the supplied evidence does not prove that host-admin-equivalent privilege is always required for the complete failing interleaving.

A SAN-side or Fibre Channel target/fabric actor may influence bad response packets that reach `qla2x00_error_entry()`, but the crash also depends on a concurrent queue teardown window. This supports a paranoid adjacent/fabric-mediated model, not ordinary AV:N Internet reachability.

No namespace-scoped privilege path is shown. The bug is hardware and deployment dependent because it requires affected qla2xxx/QLogic Fibre Channel usage, but I did not apply a broad hardware penalty beyond the explicit race/timing reduction.

4. Primitive and severity interpretation

The exact primitive is a TOCTOU-style double-read race on `ha->req_q_map[que]` resulting in a NULL pointer dereference. This is Class C invalid-state crash behavior, not Class B lifetime corruption.

The stale-use analysis does not establish active structured UAF. The patch changes the code to read the map slot once into a local variable and check that local value before use. That prevents the specific mismatch where the NULL check applies to the first read but dereference uses the second read.

Demonstrated consequence is kernel crash / denial of service. Speculative consequences such as privilege escalation, information disclosure, controlled object replacement, or post-free corruption are not supported by the supplied patch/context.

ImportantCandidate=NO because there is no established memory corruption primitive beyond NULL dereference and no unresolved repeated lifetime/refcount mutation. AutoDowngradeAllowed=YES because this is a constrained crash-only Class C issue, although manual review is still useful due to SAN-adjacent trigger uncertainty.

5. One-sentence report phrase

A double-read race in qla2x00_error_entry() can allow req_q_map to become NULL between validation and use during queue teardown, causing a NULL pointer dereference and kernel DoS in affected qla2xxx Fibre Channel environments.

6. Manual review recommendation

MANUAL CHECK RECOMMENDED

Reason: the visible primitive is crash-only NULL dereference, but the trigger involves interrupt-driven storage error handling and possible SAN/fabric-mediated input, so exposure should be confirmed for affected deployments.

7. Call-site confidence

Call-site confidence: high

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

Patch: scsi: qla2xxx: Avoid req_q_map double-read in qla2x00_error_entry()
Commit: c845f2597787ef70159a32566669e308b2807a56
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c845f2597787ef70159a32566669e308b2807a56

Commit description:

qla2x00_error_entry() reads ha->req_q_map[que] twice: once for the NULL
check and again when assigning it to req. The map slot is cleared by
qla25xx_free_req_que() (ha->req_q_map[que_id] = NULL under mq_lock)
during queue teardown, while the response-queue interrupt that drives
qla2x00_error_entry() is still registered (the IRQ is released later in
qla25xx_free_rsp_que()). If the slot is set to NULL between the two
reads, req becomes NULL and is dereferenced.

Read the slot once into req and NULL-check the local before use. mq_lock
is a mutex and cannot be taken from interrupt context, so the single
read plus local check is the appropriate fix for the reported NULL
dereference.

Fixes: a6fe35c ("[SCSI] qla2xxx: Avoid invalid request queue dereference for bad response packets.")
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-dev@google.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Link: https://patch.msgid.link/20260730155838.2119230-17-njavali@marvell.com
Signed-off-by: Martin K. Petersen (Oracle) <mkp@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/scsi/qla2xxx/qla_isr.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=c845f2597787ef70159a32566669e308b2807a56

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

The original Linux kernel CVE announcement for CVE-2026-89845 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89845

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:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 5.3

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: MODERATE
KPANIC detected for this report: NO
Published priority for this report (same as in Subject): MODERATE REGULAR

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).