[CVE-2026-74417][MODERATE 7.0] drm/radeon: fix integer overflow in radeon_align_pitch() [ Upstream

[CVE-2026-74417][MODERATE 7.0] drm/radeon: fix integer overflow in radeon_align_pitch() [ Upstream

[AL-KERNEL]

CVE: CVE-2026-74417
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: drm/radeon: fix integer overflow in radeon_align_pitch() [ Upstream
Commit: b7b44937c548c2c987fcdd129f8896741004bed6
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b7b44937c548c2c987fcdd129f8896741004bed6
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74417
Analysis date: Sat, 15 Aug 2026 20:29:34 -0400
ActionableScore: 6
ActionableScore lower bound: 3
Actionable bucket: Actionable Moderate at minimum
Manual review required: YES

Summary:
A local user with access to the Radeon DRM device can trigger an integer overflow in dumb buffer pitch calculation, potentially creating an invalid or zero sized GEM buffer and causing DoS, with paranoid review warranted for possible undersized buffer memory corruption.

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

The original Linux kernel CVE announcement for CVE-2026-74417 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74417

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-2026-74417	MODERATE	CHECK WITH IMPACT FROM ORIG NN MODERATE	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-190;CWE-680;CWE-131;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '7.8';DESCR 'An integer overflow in the DRM/Radeon dumb buffer creation path can occur in radeon_align_pitch when rounding up the pitch or multiplying the aligned value by bytes per pixel. A local process with access to the Radeon DRM device can request crafted width and bpp values that make the helper return an invalid pitch or zero, which can lead to an invalid or zero sized GEM dumb buffer. For the CVSS the PR:L is used because reliable triggering requires local access to the DRM device node, often through a logged in user session or video/render device permissions. The issue is not network reachable. Impact is at least local denial of service through invalid graphics buffer state or driver failure. For the paranoid score, the bug should be treated as a size calculation integer overflow that may produce an undersized buffer and therefore deserves manual review for possible memory corruption or privilege escalation impact.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 5)	YES	READ SIMPLEFIX HARDWARE DEBUGFS MEMORY  INCREASED_TO_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATE70_BASED_ON_ACTIONABLESCORELOWERTHAN6 DECREASED_TO_MODERATEREG_BASED_ON_FALSEPOSCHECKOFKP	NO	NO	checked

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

ActionableScore=6
ActionableScoreLower=3

## 1. ActionableScore

* Conservative score: 3
* Paranoid score: 6
* Final recommended bucket: **Actionable Moderate at minimum**::

## 2. Signal breakdown

### Conservative signals

* Local unprivileged trigger: +1
  A local process with access to the Radeon DRM device can call the dumb buffer creation ioctl with crafted width or bpp values.

* Memory corruption, weak or indirect corruption candidate: +1
  The bug is an integer overflow in pitch and size calculation. The patch does not prove an OOB write or UAF, but invalid or zero sized GEM buffers are a corruption relevant state.

* Reliable kernel crash / strong DoS concern: +1
  Invalid pitch or zero sized dumb buffer creation can plausibly lead to driver failure or kernel side graphics buffer handling errors.

Conservative total: 3

### Paranoid additional signals

* Memory layout invariant restoration: +1
  The patch restores consistency between pitch, alignment, bytes per pixel, and final GEM buffer size.

* Local high control device object API: +1
  The DRM dumb buffer API lets a local user shape kernel graphics buffer layout parameters. This applies here because the patch directly concerns attacker influenced buffer dimensions and allocation size.

* Weak LPE concern: +1
  Size calculation overflows in graphics buffer allocation paths can sometimes become undersized allocation or out of bounds access primitives, although this patch does not demonstrate a concrete write primitive.

* Integrity impact plausible: +1
  In the paranoid interpretation, an undersized or invalid GEM buffer may affect buffer contents or GPU visible memory state.

* Constrained primitive / no demonstrated target control: -1
  The patch does not show attacker controlled overwrite target, controlled payload, UAF reclaim, type confusion, or arbitrary write.

Paranoid total: 6

## 3. Reachability analysis

The bug is local and requires access to the Radeon DRM device node, typically `/dev/dri/card*` or a related DRM node. On desktop systems this may be available to logged in users through graphics device permissions, so PR:L is the practical CVSS interpretation. It is not network reachable.

Containers usually do not get DRM device access unless the device is explicitly passed through and allowed by device cgroup policy. The affected path is default only on systems using the Radeon DRM driver and matching hardware, so exposure is hardware dependent but reachable through an ordinary local ioctl when present.

Call-site confidence: high. The provided patch includes both `radeon_align_pitch()` and its use in `radeon_mode_dumb_create()`.

## 4. Severity interpretation

This is stronger than an ordinary Moderate cleanup because it is an integer overflow in a graphics buffer size calculation path. Conservative handling should not assume privilege escalation because the patch only states invalid pitch or zero sized buffer, not a proven OOB write or UAF.

The paranoid interpretation should still keep this for manual review because undersized or invalid GEM buffer creation can be a meaningful memory safety precursor in GPU drivers. It is not a Strong Important candidate without more evidence of controllable memory corruption, but it is an Actionable Moderate at minimum.

## 5. One-sentence report phrase

A local user with access to the Radeon DRM device can trigger an integer overflow in dumb buffer pitch calculation, potentially creating an invalid or zero sized GEM buffer and causing DoS, with paranoid review warranted for possible undersized buffer memory corruption.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

Reason: this is not a pure resource leak or validation-only warning. It is an integer overflow in a kernel graphics buffer allocation path, and the patch context supports possible undersized or invalid buffer state even though a concrete privilege escalation primitive is not demonstrated.

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

Patch: drm/radeon: fix integer overflow in radeon_align_pitch() [ Upstream
Commit: b7b44937c548c2c987fcdd129f8896741004bed6
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b7b44937c548c2c987fcdd129f8896741004bed6

Changed files:
  drivers/gpu/drm/radeon/radeon_gem.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=b7b44937c548c2c987fcdd129f8896741004bed6

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

The original Linux kernel CVE announcement for CVE-2026-74417 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74417

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:N/I:N/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: 3
  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: NO
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).