[CVE-2026-89864][MODERATE 7.0] scsi: qla2xxx: Bound i2c->length in I2C bsg handlers

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

CVE: CVE-2026-89864
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: scsi: qla2xxx: Bound i2c->length in I2C bsg handlers
Commit: 8f01f886cc5e7bbc16cbf1a9928fdebbc911e973
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8f01f886cc5e7bbc16cbf1a9928fdebbc911e973
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89864
Analysis date: Wed, 16 Sep 2026 09:46:29 -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-2026-89864 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89864

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.

======================================================================
AL-KERNEL CLASSIFICATION RESULT
======================================================================

CVE-2026-89864	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-89864 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:H';*CWE-787;CWE-125;CWE-121;CWE-122;*CWE-20;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H';BEST CVSS score: '7.8';DESCR 'The qla2xxx I2C BSG handlers used a user supplied 16 bit length with fixed size stack and DMA buffers. In the write path an oversized length can over read the on stack qla_i2c_access buffer and overwrite the 256 byte sfp DMA buffer before an oversized DMA transfer. In the read path an oversized length can DMA beyond the 256 byte sfp buffer and then overflow the 64 byte buffer inside the on stack request object. For the CVSS the PR:L is used in the paranoid score because CAP_SYS_RAWIO or delegated bsg device access may be available to a restricted local service or reduced capability administrator rather than only full root. The issue is not network reachable. Impact is kernel memory corruption with likely denial of service and a plausible path to privilege escalation, so manual review is required.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate / Strong Important candidate requiring manual review (with actual score 6)	YES	OOB DMAorINTERRUPT HARDWARE LINUS KPANIC  KPANIC INCREASED_TO_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATE7_BASED_ON_FALSEPOSCHECKOFDH	NO	NO	checked

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

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

1. ActionableScore

* Raw conservative score: 4
* Conservative score: 5
* Applied conservative floor/cap: manual review safety floor for controlled kernel memory corruption, 4 -> 5
* Raw paranoid score: 6
* Paranoid score: 6
* Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**::

2. Signal breakdown

Conservative signals:

* +2 Strong corruption primitive. The patch establishes attacker supplied i2c length causing heap overwrite of the 256 byte sfp DMA buffer and stack overflow of the 64 byte buffer inside the on stack qla_i2c_access object.
* +1 Reliable kernel crash / strong DoS. Kernel heap and stack corruption is realistically crash capable.
* +1 Privileged kernel/device-management memory corruption path. The vulnerable operation involves SCSI BSG I2C handlers, DMA pool storage, and oversized DMA transfers.
* +1 Memory layout invariant restoration. The fix restores consistency between the 16 bit user supplied length, the fixed 64 byte request buffer, and the 256 byte DMA buffer before memcpy or DMA.
* -1 Reduced / delegated privilege. The supplied evidence says the caller needs CAP_SYS_RAWIO, which is a powerful local capability but may be delegated to a restricted service or reduced capability administrator rather than always implying full host root.

Paranoid additional signal:

* +2 Strong LPE plausibility / exploitation leverage. The primitive is not only a NULL dereference or warning. It includes kernel stack and heap overwrite with attacker controlled length and partially attacker influenced data, making privilege escalation technically plausible even though no exploit chain is demonstrated.

Important non-awarded signals:

* RealUAF not awarded because this is bounds corruption, not a lifetime bug.
* Remote reachability not awarded because the vulnerable path is a local SCSI BSG control interface.
* Local unprivileged trigger not awarded because CAP_SYS_RAWIO or equivalent device access is required.
* Arbitrary write not awarded because target selection and full payload control are not demonstrated.
* Confidentiality impact not separately awarded because the stack over-read is not shown to be disclosed back to userspace.
* Extra Availability not awarded because the same crash-capable corruption is already counted once.
* Race or timing penalty not applied because this is an ordered invalid length path, not a timing race.
* Hardware rarity penalty not applied merely because qla2xxx is a hardware driver.

3. Reachability analysis

The complete trigger requires access to the qla2xxx I2C BSG handler and the supplied description explicitly states that a caller holding CAP_SYS_RAWIO can use the bug. This is local reachability through a device/control interface, not packet-triggered network reachability.

HostAdminRequired is UNKNOWN rather than YES because CAP_SYS_RAWIO is a strong host capability, but the evidence does not prove that only full host administrator context can reach the device node in every deployment. It may be exposed to a storage-management daemon, restricted service account, or reduced capability administrator. NamespaceScopedPrivilege is NO because there is no evidence that this SCSI BSG device-management operation is fully performable with attacker-created namespace-scoped capabilities.

Prior setup requires the affected qla2xxx driver and device path to exist. This is hardware dependent, but the prompt evidence does not justify treating it as physical-only or rare enough for a scoring penalty. No race repeatability issue is involved.

4. Primitive and severity interpretation

The exact primitive is attacker-influenced out-of-bounds memory access in kernel context. In the write path, an oversized length causes memcpy from the on-stack qla_i2c_access buffer into the 256 byte sfp DMA buffer, producing stack over-read and heap overwrite before an oversized DMA transfer. In the read path, the device/DMA operation can write beyond the 256 byte sfp buffer and the subsequent memcpy can overflow the 64 byte buffer inside the on-stack request object.

This is active kernel memory corruption, not fixed crash-only invalid state. It is not a cleanup-only stale dereference and no repeated release/refcount operation exists. PrimitiveClass is CLASS_A because the patch directly establishes stack and heap corruption through an attacker supplied length.

The demonstrated consequence is kernel memory corruption with likely DoS. The speculative but technically plausible consequence is local privilege escalation, because kernel stack and heap overwrite primitives can often be security-relevant. Controlled reclaim, arbitrary write, and a complete LPE chain are not demonstrated, so the score is kept at ActionableScore 6 rather than 7 or higher.

ImportantCandidate is YES because this is a strong kernel corruption primitive. AutoDowngradeAllowed is NO because automatic closure would discard a concrete stack/heap corruption issue with unresolved exploitation leverage.

5. One-sentence report phrase

The qla2xxx I2C BSG handlers trusted a user supplied 16 bit length for fixed stack and DMA buffers, allowing a CAP_SYS_RAWIO capable local caller to corrupt kernel heap and stack memory and requiring manual review for possible privilege escalation.

6. Manual review recommendation

MANUAL CHECK REQUIRED

Reason: this is concrete local kernel stack and heap memory corruption, not a simple crash-only NULL dereference or resource leak, and the privilege boundary may be delegated below full host root in real deployments.

7. Call-site confidence

Call-site confidence: high

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

Patch: scsi: qla2xxx: Bound i2c->length in I2C bsg handlers
Commit: 8f01f886cc5e7bbc16cbf1a9928fdebbc911e973
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8f01f886cc5e7bbc16cbf1a9928fdebbc911e973

Commit description:

struct qla_i2c_access carries a 16-bit length field alongside a fixed
64-byte buffer:

	struct qla_i2c_access {
		uint16_t device, offset, option, length;
		uint8_t  buffer[0x40];
	} __packed;

qla2x00_write_i2c() and qla2x00_read_i2c() use the user-supplied
i2c->length without any bounds check. i2c is overlaid on a 256-byte
on-stack buffer and sfp is a 256-byte DMA-pool buffer, so a length up to
65535 overruns both:

  - write: memcpy(sfp, i2c->buffer, i2c->length) over-reads the stack and
    over-writes the sfp heap buffer, and qla2x00_write_sfp() then DMAs
    i2c->length bytes out of the 256-byte buffer.
  - read: qla2x00_read_sfp() DMAs i2c->length bytes into the 256-byte sfp,
    then memcpy(i2c->buffer, sfp, i2c->length) overflows the 64-byte
    buffer inside the on-stack array.

A caller holding CAP_SYS_RAWIO can use this to corrupt the heap and the
kernel stack. Reject requests whose length exceeds the buffer before any
copy or DMA transfer in both handlers.

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/20260730155838.2119230-33-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=8f01f886cc5e7bbc16cbf1a9928fdebbc911e973

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

The original Linux kernel CVE announcement for CVE-2026-89864 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89864

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:H/I:H/A:H
  The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
  The Best / paranoid CVSS score: 7.8

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).