[CVE-2026-89853][MODERATE 7.0] scsi: qla2xxx: Fix FCE trace use-after-free during firmware dump

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

CVE: CVE-2026-89853
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: scsi: qla2xxx: Fix FCE trace use-after-free during firmware dump
Commit: 423487f03e325b8665d20a2a3171fe012b1a4fa9
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=423487f03e325b8665d20a2a3171fe012b1a4fa9
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89853
Analysis date: Wed, 16 Sep 2026 08:05:28 -0400
ActionableScore: 4
ActionableScore lower bound: 3
Actionable bucket: Borderline / manual review recommended
Manual review required: YES

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-89853 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89853

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 7.0
Manual review required: YES

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-2026-89853	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-89853 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:H/I:H/A:H';*CWE-416;CWE-362;CWE-667;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:H';BEST CVSS score: '7';DESCR 'A use-after-free race exists in the qla2xxx FCE trace handling path. qla2x00_free_fce_trace() could free the FCE DMA buffer while firmware dump consumers such as qla27xx_fwdt_entry_t264() and qla25xx_copy_fce() were checking and copying the same buffer under a different lock. A local actor able to disable FCE tracing through debugfs or otherwise control adapter diagnostic state could race this with a firmware dump and trigger a kernel crash or stale memory copy. For the CVSS the PR:L value is used in the paranoid score because some deployments may delegate debugfs or adapter control to reduced capability root or service accounts, although typical systems restrict it to administrators. The issue is not directly network reachable and requires local control plane interaction with the qla2xxx driver. Impact is at least local denial of service via kernel crash and in worst case may allow confidentiality or integrity impact because the bug class is a UAF around a freed DMA buffer.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline / manual review recommended (with actual score 4)	YES	LOCK INIT RACE UAF DMAorINTERRUPT HARDWARE DEBUGFS LINUS KPANIC MEMORY 	YES	NO	checked

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

ActionableScore=4
ActionableScoreLower=3
PrimitiveClass=CLASS_B
RealUAF=YES
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=RECOMMENDED
AutoDowngradeAllowed=YES

1. ActionableScore

* Raw conservative score: 3
* Conservative score: 3. No floor or cap applied.
* Raw paranoid score: 4
* Paranoid score: 4. No floor or cap applied.
* Final recommended bucket: **Borderline / manual review recommended**::

2. Signal breakdown

Conservative positive signals:

* +2 Real UAF / lifetime violation. The patch directly establishes that `qla2x00_free_fce_trace()` could free the FCE DMA buffer while firmware dump readers still use `ha->fce` after a NULL check under a different lock.
* +1 Reliable kernel crash / strong DoS. A stale DMA-buffer read/copy during firmware dump can plausibly fault or crash the kernel.

Paranoid additional signal:

* +1 Confidentiality plausible. The stale use is not only a NULL dereference but a copy of the freed FCE buffer into firmware-dump data. If that dump is later exposed to the triggering actor or another lower-privileged actor, stale kernel/DMA contents could become visible. This is plausible but not fully established from the supplied patch alone.

Non-awarded or withheld signals:

* +0 Remote reachable. No direct network trigger is established.
* +0 Local unprivileged trigger. Below-host-admin reachability is not established.
* +0 Strong LPE / strong exploitation leverage. No controlled reclaim, object replacement, arbitrary write, callback control, or credential impact is shown.
* +0 Structured stale-object leverage. The stale object is a fixed DMA buffer, not an active structured object whose fields drive later kernel decisions.
* +0 Concrete repeated release/refcount. There is no second `put`, `free`, `kref_put`, or refcount mutation on the same dangling reference.
* +0 Extra availability. The crash/DoS is already counted once.
* No race penalty was applied. The bug is a race, but the supplied evidence does not prove that the timing is narrow, one-shot, or externally uncontrollable enough to subtract a point.

Repeated release/refcount check:

* First release can end lifetime: yes, `dma_free_coherent()` frees the FCE DMA buffer.
* Exact same reference survives for a second lifetime mutation: no, the concurrent path copies from the stale pointer but does not perform a second free/put.
* Second operation mutates lifetime/refcount: no.
* Concrete repeated release/refcount +1 awarded: no.
* Paranoid repeated-refcount leverage +1 awarded: no.
* FLOOR 5 applied: no.

3. Reachability analysis

The evident trigger requires local control-plane interaction with the qla2xxx diagnostic/FCE trace state, specifically a debugfs FCE disable racing with a firmware dump. Debugfs and HBA diagnostic controls are commonly administrator-controlled, but the exact permission model for the complete trigger path is not visible in the supplied patch. Therefore HostAdminRequired is UNKNOWN rather than YES.

No namespace-scoped capability path is shown. There is no evidence that an attacker can create a namespace and perform all required operations there. NamespaceScopedPrivilege is NO for the supplied evidence.

There is no direct TCP/IP or remote packet-processing path. Fibre Channel or firmware/device activity may influence when dumps occur, but the described vulnerability depends on local FCE disable and firmware-dump handling, not direct remote network input.

The bug is hardware/subsystem specific to qla2xxx, but no rare-hardware penalty is applied because the prompt does not establish that the required device is unusually rare or physically attacker-controlled only.

4. Primitive and severity interpretation

The exact primitive is a race-based use-after-free of a fixed coherent DMA buffer. One path frees and clears `ha->fce` while holding only `fce_mutex`; firmware-dump paths check and copy `ha->fce` under `hardware_lock` and do not take `fce_mutex`. The fix unpublishes the pointer under `hardware_lock` before freeing it, making the lifetime ordering consistent with the readers.

This is Class B because it is a real kernel lifetime violation, but it is constrained. The stale object is fixed stale storage rather than an active structured object. The demonstrated consequence is kernel crash or stale-buffer copy during diagnostic dump. The speculative consequence is limited information exposure through firmware-dump contents if access to the dump is available to a relevant attacker.

ImportantCandidate is NO because the supplied evidence does not establish controlled reclaim, arbitrary read/write, privilege escalation, active structured reuse, callback influence, security-boundary bypass, or repeated lifetime/refcount mutation. Manual review is still recommended because it is a real UAF in kernel driver code and the stale copy path may deserve product-specific review for dump accessibility.

AutoDowngradeAllowed is YES because this appears to be a constrained fixed-buffer UAF with no unresolved strong exploitation primitive beyond crash/stale copy.

5. One-sentence report phrase

A race in qla2xxx FCE trace handling can free the FCE DMA buffer while firmware-dump code is still copying it, causing a local use-after-free that may crash the kernel and may warrant review for possible stale dump-data exposure.

6. Manual review recommendation

MANUAL CHECK RECOMMENDED

The issue is a real race-based UAF, but current evidence supports a constrained fixed-buffer crash/stale-copy primitive rather than a strong Important-class exploitation primitive.

7. Call-site confidence

Call-site confidence: medium

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

Patch: scsi: qla2xxx: Fix FCE trace use-after-free during firmware dump
Commit: 423487f03e325b8665d20a2a3171fe012b1a4fa9
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=423487f03e325b8665d20a2a3171fe012b1a4fa9

Commit description:

qla2x00_free_fce_trace() freed and cleared ha->fce while holding only
fce_mutex. The firmware-dump consumers qla27xx_fwdt_entry_t264() and
qla25xx_copy_fce() read ha->fce (NULL check followed by a copy of the
buffer) under hardware_lock and never take fce_mutex. A debugfs FCE
disable could therefore free the DMA buffer between a dump's NULL check
and its copy, resulting in a use-after-free.

Unpublish ha->fce under hardware_lock, then release the lock and free
the DMA buffer (dma_free_coherent() may sleep). A concurrent dump either
completes its check and copy with the buffer still valid, or observes
ha->fce == NULL and skips it.

Fixes: 841df27 ("scsi: qla2xxx: Move FCE Trace buffer allocation to user control")
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/20260730155838.2119230-11-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_init.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=423487f03e325b8665d20a2a3171fe012b1a4fa9

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

The original Linux kernel CVE announcement for CVE-2026-89853 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89853

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:L/I:N/A:H
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
  The Best / paranoid CVSS score: 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: 3
  Paranoid ActionableScore: 4

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: YES
Published priority for this report (same as in Subject): MODERATE 7.0

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).