[CVE-2026-53203][IMPORTANT] accel/ivpu: Add buffer overflow check in MS get_info_ioctl

[CVE-2026-53203][IMPORTANT] accel/ivpu: Add buffer overflow check in MS get_info_ioctl

[AL-KERNEL]

CVE: CVE-2026-53203
Priority: IMPORTANT
AL-KERNEL base severity: IMPORTANT
KPANIC flag: YES
Patch: accel/ivpu: Add buffer overflow check in MS get_info_ioctl
Commit: d3c12ed33e8923f3090909a1738f3e59292996a6
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d3c12ed33e8923f3090909a1738f3e59292996a6
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53203
Analysis date: Thu, 25 Jun 2026 20:38:46 -0400
ActionableScore: 7
ActionableScore lower bound: 6
Actionable bucket: Strong Important candidate / Actionable Moderate at minimum
Manual review required: YES

Summary:
A local ivpu device user can trigger a firmware-size driven buffer overflow in the metric stream get_info ioctl when info_size exceeds the actual BO allocation, causing at least kernel memory corruption or DoS and requiring manual review for possible LPE.

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ABOUT THIS REPORT
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The original Linux kernel CVE announcement for CVE-2026-53203 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53203

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: IMPORTANT
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-2026-53203	IMPORTANT	CHECK	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-120;*CWE-20;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7.8';DESCR 'A buffer overflow risk exists in the ivpu metric stream get_info ioctl because the firmware reported info_size was compared with the user supplied buffer_size but was not checked against the actual allocated buffer object size. A local process with access to the ivpu accel device can provide a buffer object that is smaller than the returned metric stream info while still passing a larger buffer_size, which may let the driver proceed with an incorrect copy beyond the allocated buffer. For the CVSS the PR:L is used because triggering requires local access to the ivpu ioctl path through a process that can open the accelerator device, but it does not normally require full administrator privileges. The issue is not network reachable. Impact is at least denial of service via memory corruption or kernel crash, and a higher integrity or confidentiality impact is plausible enough for manual review because the patch context explicitly addresses a buffer overflow condition.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Strong Important candidate / Actionable Moderate at minimum (with actual score 7)  SKIP CVE-2026-53203  SKIP The Fixes patch not applied yet, so unlikely that actual: cdfad4db7756563db7d458216d9e3c2651dddc7d YES  NO NO unknown 	MAYBE	OOB SIMPLEFIX KPANIC  KPANIC INCREASED_TO_HIGH_BASED_ON_GUESSCVSS	-	-	checked

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

ActionableScore=7
ActionableScoreLower=6

## 1. ActionableScore

* Conservative score: 6
* Paranoid score: 7
* Final recommended bucket: **Strong Important candidate / Actionable Moderate at minimum**::

## 2. Signal breakdown

* Local unprivileged trigger: +1
  The bug is reachable through the ivpu metric stream get_info ioctl by a local process with access to the accel or DRM device node.

* Firmware-mediated external influence: +1
  The dangerous size value is returned from firmware. This is not network reachable, but the kernel trusts firmware-provided metadata in a device-management path.

* Constrained kernel buffer overwrite: +1 conservative
  The patch explicitly prevents proceeding when firmware returned info_size exceeds the allocated BO size. The overflow target appears to be a driver buffer object, but target and payload control are not clearly arbitrary.

* Generic memory corruption: +2 paranoid
  The commit describes a buffer overflow check, and the missing bound is against the actual allocation size. For paranoid triage this is defensibly treated as kernel memory corruption.

* Weak LPE concern: +1 conservative
  A local ioctl-accessible buffer overflow in a kernel accelerator driver can plausibly become more than a crash, but the patch does not show a demonstrated reclaim, arbitrary write, or controlled target primitive.

* Privilege escalation plausible: +2 paranoid
  For the paranoid score, a kernel buffer overflow reachable by a local device-node user is enough to avoid auto-closing without manual review.

* Privileged kernel/device-management memory corruption path: +1
  The corruption occurs in a trusted accelerator driver path involving firmware-fed metadata and kernel-managed BO allocation state.

* Reliable kernel crash / strong DoS: +1
  Proceeding with a copy larger than the allocated BO can realistically crash or corrupt kernel/device memory.

* Integrity impact plausible: +1 conservative
  Out-of-bounds writes can corrupt adjacent state, although the exact target is not demonstrated.

* Rare AND difficult-to-reach subsystem/configuration: -1
  Exposure depends on Intel ivpu hardware, NPU profiling support, and access to the relevant device node.

## 3. Reachability analysis

The likely attacker is a local user or local process that can open the ivpu accel or DRM device and invoke the metric stream get_info ioctl. This should not be scored as PR:H by default, because accelerator or render-style device nodes are often exposed to non-root local users through device ACLs or groups. It is not remotely network reachable.

Namespaces and containers may matter if the device node is passed into a container. A container user with access to the ivpu device could potentially reach the same ioctl path without full host-root privileges. The path is not universally default-exposed because it requires affected hardware, the ivpu driver, and NPU profiling support introduced by the referenced commit.

## 4. Severity interpretation

This is stronger than an ordinary Moderate because the patch fixes an allocation-size check missing before a buffer copy in a kernel driver ioctl path. The realistic evidence supports local DoS and constrained memory corruption. The paranoid interpretation treats it as an Important candidate because local kernel buffer overflows in device drivers can sometimes be turned into privilege escalation, even when the immediate patch does not demonstrate arbitrary write or object-reclaim control.

Overall, this should not be auto-closed as a low-risk crash-only issue.

## 5. One-sentence report phrase

A local ivpu device user can trigger a firmware-size driven buffer overflow in the metric stream get_info ioctl when info_size exceeds the actual BO allocation, causing at least kernel memory corruption or DoS and requiring manual review for possible LPE.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

Reason: the patch explicitly fixes a buffer overflow boundary check in a local ioctl-accessible kernel accelerator driver path, with firmware-fed size metadata and plausible local privilege escalation concern despite limited evidence of a strong controlled-write primitive.

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

Patch: accel/ivpu: Add buffer overflow check in MS get_info_ioctl
Commit: d3c12ed33e8923f3090909a1738f3e59292996a6
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d3c12ed33e8923f3090909a1738f3e59292996a6

Commit description:

Add validation that the info size returned from the metric stream info
query is not exceeded when checked against the allocated buffer size.
If the firmware returns a size larger than the buffer, reject the
operation with -EOVERFLOW instead of proceeding with an incorrect
buffer copy.

Fixes: cdfad4d ("accel/ivpu: Add NPU profiling support")
Cc: stable@vger.kernel.org # v6.18+
Signed-off-by: Andrzej Kacprowski <andrzej.kacprowski@linux.intel.com>
Reviewed-by: Karol Wachowski <karol.wachowski@linux.intel.com>
Signed-off-by: Karol Wachowski <karol.wachowski@linux.intel.com>
Link: https://patch.msgid.link/20260529120841.135852-1-andrzej.kacprowski@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/accel/ivpu/ivpu_ms.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=d3c12ed33e8923f3090909a1738f3e59292996a6

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

The original Linux kernel CVE announcement for CVE-2026-53203 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53203

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: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: 6
  Paranoid ActionableScore: 7

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: IMPORTANT
KPANIC detected for this report: YES
Published priority for this report (same as in Subject): IMPORTANT

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).