[CVE-2026-89865][MODERATE 7.0] scsi: qla2xxx: Zero SFP DMA buffer in FRU/I2C bsg handlers

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

CVE: CVE-2026-89865
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: scsi: qla2xxx: Zero SFP DMA buffer in FRU/I2C bsg handlers
Commit: a476377a66897549dd49bee319f4df66623417b7
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a476377a66897549dd49bee319f4df66623417b7
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89865
Analysis date: Wed, 16 Sep 2026 07:40:37 -0400
ActionableScore: 6
ActionableScore lower bound: 5
Actionable bucket: Actionable Moderate / Strong Important candidate requiring manual review
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-2026-89865 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89865

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
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CVE-2026-89865	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-89865 CHECK WITH IMPACT FROM ORIG NN 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:H/I:H/A:L';CWE-908;*CWE-200;CWE-665;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L';BEST CVSS score: '7.3';DESCR 'qla2xxx FRU and I2C bsg handlers allocate a 256 byte DMA bounce buffer with dma_pool_alloc and initialize only a small prefix before passing it to qla2x00_write_sfp. A local actor with access to the qla2xxx bsg interface can influence the transfer length through the first payload byte, causing the device to DMA read beyond the initialized region and write stale DMA pool heap bytes into device flash. For the CVSS the PR:L is used because reliable triggering requires local access to the bsg device or an equivalent delegated storage management path, but not necessarily full administrator control of the host. The issue is not network reachable through packet traffic and requires local control plane access to the Fibre Channel adapter interface. Impact is at least kernel memory exposure to the device and persistent device data corruption, with possible confidentiality and integrity impact if the flash contents can be read back or if the leaked heap bytes contain sensitive kernel data.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate / Strong Important candidate requiring manual review (with actual score 6)	YES	DMAorINTERRUPT HARDWARE LINUS KPANIC MEMORY  KPANIC INCREASED_TO_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATE7_BASED_ON_FALSEPOSCHECKOFKP	NO	NO	checked

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

ActionableScore=6
ActionableScoreLower=5
PrimitiveClass=CLASS_B
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=NO
ImportantCandidate=YES
ManualReview=REQUIRED
AutoDowngradeAllowed=NO

1. ActionableScore

* Raw conservative score: 5
* Conservative score: 5
* Raw paranoid score: 6
* Paranoid score: 6
* Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**::

No floor or cap was applied. The paranoid score is emitted as ActionableScore because the primitive is a concrete kernel heap exposure to device flash with unresolved readback and persistence implications.

2. Signal breakdown

Positive conservative signals:

* +1. Constrained DMA disclosure primitive. A 256 byte DMA pool buffer is only partially initialized, but the device can DMA read up to 255 bytes from it.
* +1. Confidentiality plausible. Stale DMA pool heap bytes leave the intended initialized region and are written into device flash, creating a concrete disclosure sink outside normal kernel memory.
* +1. Integrity plausible. User influenced transfer length can cause stale heap bytes to be written into FRU/I2C/SFP flash beyond the intended initialized payload.
* +1. Attacker influenced active length control. The first user controlled payload byte can become the effective transfer length in qla2x00_write_sfp.
* +1. Practical chain to meaningful consequence. The described sequence is not merely a crash path: local bsg input controls length, hardware DMA reads uninitialized kernel heap bytes, and persistent device flash is modified.

Paranoid additional signal:

* +1. Manual review sensitive kernel heap exposure. If the same or related FRU/I2C interfaces allow reading back the affected flash contents, the stale DMA pool bytes become a practical kernel memory disclosure path. This is technically supported by the read/write FRU/I2C handler context but needs manual confirmation.

Important non-awarded signals:

* +0. RealUAF not awarded. No object lifetime violation or stale post-free dereference is established.
* +0. Controlled reclaim not demonstrated.
* +0. Arbitrary kernel read or write not demonstrated.
* +0. Remote reachability not established. This is local device control plane access, not packet-triggered networking.
* +0. Reliable kernel crash not awarded. The demonstrated consequence is stale heap exposure and flash corruption, not a host panic.
* +0. Extra availability not awarded. Persistent flash corruption may affect device behavior, but host-wide DoS is not established.
* +0. CLASS_A not used. The disclosure and flash corruption are concrete, but target selection and payload/contents control are constrained and no demonstrated LPE, arbitrary R/W, or broad boundary bypass is supplied.

3. Reachability analysis

The apparent trigger is local access to qla2xxx bsg FRU/I2C handlers. The attacker must be able to submit the relevant bsg request to the Fibre Channel adapter interface and control the payload byte that later becomes the transfer length.

HostAdminRequired is UNKNOWN. The supplied input does not prove that full host root or host-admin-equivalent privilege is always required, but it also does not prove ordinary unprivileged reachability. Device node permissions, udev policy, group membership, CAP_SYS_RAWIO-like restrictions, and storage-management delegation need product-specific verification.

NamespaceScopedPrivilege is NO. The affected operation targets a physical qla2xxx adapter management interface and is not shown to be fully performable inside attacker-created namespaces.

Prior host setup likely exists in the operational sense because the qla2xxx hardware and bsg interface must be present and exposed. This was not scored as a strong negative because a physical adapter driver path is not automatically rare or unreachable, and the patch does not establish a physical-only attacker interaction beyond local control plane access.

No race is involved. The trigger is an ordered input and length-handling issue, not a timing window.

4. Primitive and severity interpretation

The exact primitive is an uninitialized DMA pool memory exposure. The driver allocates a DMA bounce buffer with dma_pool_alloc, initializes only a small prefix, and then permits qla2x00_write_sfp to expand the transfer length from a user-controlled first byte. The device DMA reads beyond the initialized prefix and writes stale DMA pool heap bytes into persistent device flash.

This is fixed stale DMA storage rather than an active structured UAF. There is no repeated release/refcount operation. There is no evidence that the first operation frees an object or that a second lifetime mutation occurs.

The demonstrated consequence is kernel heap exposure to device-visible persistent storage plus device flash corruption. The speculative consequence is stronger confidentiality impact if the stale flash contents are readable by the same or another attacker-accessible management path, and stronger integrity/availability impact if corrupted FRU/I2C/SFP data affects adapter operation.

PrimitiveClass is CLASS_B because a concrete non-crash kernel confidentiality/integrity primitive exists, but it is constrained by DMA buffer size, device mediation, unclear readback path, unclear permissions, and lack of arbitrary kernel R/W or controlled reclaim.

ImportantCandidate is YES because this is not a simple warning or DoS-only bug. It exposes stale kernel heap bytes outside the kernel through DMA and persists them into device flash.

AutoDowngradeAllowed is NO because automatic downgrade would risk losing a concrete kernel heap exposure and persistent device-state corruption primitive whose practical readback and permission boundaries need manual verification.

Likely operational severity is Actionable Moderate at minimum, with Strong Important candidacy depending on bsg permissions, readback capability, sensitivity of leaked DMA pool contents, and operational impact of flash corruption.

5. One-sentence report phrase

qla2xxx FRU/I2C bsg handlers can expose stale DMA pool heap bytes to device flash because a user influenced length may make the adapter DMA read beyond the initialized prefix of a 256 byte bounce buffer, requiring manual review of bsg permissions and flash readback impact.

6. Manual review recommendation

MANUAL CHECK REQUIRED

Reason: the bug establishes concrete kernel heap exposure through DMA and persistent device flash modification, while the practical attacker privilege boundary and readback path are product and deployment dependent.

7. Call-site confidence

Call-site confidence: high

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

Patch: scsi: qla2xxx: Zero SFP DMA buffer in FRU/I2C bsg handlers
Commit: a476377a66897549dd49bee319f4df66623417b7
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a476377a66897549dd49bee319f4df66623417b7

Commit description:

The FRU and I2C bsg handlers stage their transfer in a DMA_POOL_SIZE
(256-byte) bounce buffer obtained from dma_pool_alloc(), which does not
zero the allocation. They initialize only a few leading bytes before
handing the buffer to qla2x00_write_sfp().

qla2x00_write_sfp() can override the transfer length with a user-supplied
value:

	if (len == 1)
		opt |= BIT_0;
	if (opt & BIT_0)
		len = *sfp;

*sfp is the first byte of the (user-controlled) payload, so len can grow
up to 255. The device then DMA-reads len bytes from the 256-byte pool
buffer. Since only a small prefix was written
(e.g. MAX_FRU_SIZE == 36 bytes for a FRU version, one byte for a FRU
status register), the hardware reads past the initialized region and
writes up to ~219 bytes of stale DMA-pool heap memory to the device
flash.

Allocate the buffer with dma_pool_zalloc() in all five FRU/I2C handlers
so any bytes beyond the initialized data are zero rather than stale heap
contents.

Fixes: 697a4bc ("[SCSI] qla2xxx: Provide method for updating I2C attached VPD.")
Fixes: 9ebb5d9 ("[SCSI] qla2xxx: Add I2C BSG interface.")
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/20260730155838.2119230-32-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_bsg.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=a476377a66897549dd49bee319f4df66623417b7

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

The original Linux kernel CVE announcement for CVE-2026-89865 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89865

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:L/UI:N/S:U/C:L/I:L/A:L
  The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L
  The Best / paranoid CVSS score: 7.3

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: 5
  Paranoid ActionableScore: 6

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).