[CVE-2025-71294][LOW] drm/amdgpu: fix NULL pointer issue buffer funcs [ Upstream

[CVE-2025-71294][LOW] drm/amdgpu: fix NULL pointer issue buffer funcs [ Upstream

[AL-KERNEL]

CVE: CVE-2025-71294
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: drm/amdgpu: fix NULL pointer issue buffer funcs [ Upstream
Commit: 29fd416e0e08aa6d5a97fd313749d08d83de0826
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=29fd416e0e08aa6d5a97fd313749d08d83de0826
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2025-71294
Analysis date: Sat, 01 Aug 2026 12:49:17 -0400
ActionableScore: 2
ActionableScore lower bound: 0
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
A NULL pointer dereference in AMDGPU device initialization can occur when SDMA is disabled and `buffer_funcs_ring` is not initialized, causing a local denial of service during driver initialization or reinitialization.

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

The original Linux kernel CVE announcement for CVE-2025-71294 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2025-71294

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: LOW
Manual review required: NO

A detailed explanation of the methodology and priority rules is included
at the end of this message.

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

CVE-2025-71294	LOW	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:N/I:N/A:H';**CWE-476;CWE-754;CWE-703;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.5';DESCR 'amdgpu_device_ip_init could dereference adev mman buffer_funcs_ring when the SDMA block is disabled and the buffer functions ring was never initialized. This can cause a NULL pointer dereference during AMDGPU device initialization or reinitialization and may prevent the GPU driver from loading or may crash the kernel depending on configuration. For the CVSS the PR:H is used for the base score because reliable triggering normally requires administrative control over driver load, module parameters, or hardware initialization state. A paranoid PR:L interpretation is only for environments where a local user can indirectly force GPU recovery or reinitialization through delegated GPU access. The issue is not network reachable. Impact is denial of service only, with no supported path to information disclosure or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1)  SKIP CVE-2025-71294  SKIP No affected files built, so skip this CVE NO  - - unknown 	MAYBE	HARDWARE  INCREASED_FROM_LOW_BASED_ON_HIGHCVSSSCORE DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	-	-	checked

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

ActionableScore=2
ActionableScoreLower=0

## 1. ActionableScore

* Conservative score: 0
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate / Low-like**::

## 2. Signal breakdown

Conservative signals:

* Reliable kernel crash / strong DoS: +1. The patch prevents a direct NULL dereference of `adev->mman.buffer_funcs_ring` during `amdgpu_device_ip_init()`.
* Requires admin/root/CAP in typical deployments: -2. Reliable triggering normally requires control over driver initialization, module parameters, hardware state, or device reset paths.
* Rare or configuration dependent condition: -1. The bug requires SDMA to be disabled or unavailable so that `buffer_funcs_ring` is not initialized.
* Floor applied: score does not go below 0.

Paranoid signals:

* Local unprivileged trigger: +1. In some systems a local GPU user might indirectly provoke GPU recovery or reinitialization, but this is not demonstrated by the patch.
* Reliable kernel crash / strong DoS: +1. A NULL pointer dereference can crash or break the GPU driver initialization path.
* Broadly deployed subsystem: +1. AMDGPU is a common DRM driver on AMD GPU systems.
* Rare or configuration dependent condition: -1. The vulnerable state depends on SDMA being disabled or not initialized.

Not counted:

* No generic memory corruption. This is a NULL pointer dereference, not UAF, OOB write, double free, type confusion, or controlled overwrite.
* No privilege escalation signal. The patch does not show attacker controlled reclaim, object replacement, callback control, arbitrary write, or refcount abuse.
* No confidentiality or integrity signal. There is no readback, information disclosure, or write primitive.
* No remote or firmware mediated external trigger is counted. The condition is hardware or driver configuration dependent, but not realistically network reachable.

## 3. Reachability analysis

The affected path is AMDGPU device initialization or reinitialization. In the normal case, triggering this requires privileged control over driver load, device bringup, kernel parameters, firmware or hardware configuration, or administrative reset operations. A local unprivileged user with GPU access may be able to cause GPU hangs or recovery in some environments, but the patch does not demonstrate that this reaches `amdgpu_device_ip_init()` reliably. Namespaces do not materially lower privileges unless the deployment delegates GPU device control or reset capability into a container. The path is not network reachable and depends on an AMDGPU system with SDMA disabled or otherwise not initializing `buffer_funcs_ring`.

Call-site confidence: medium. The direct dereference and fix are visible, but full reset and recovery call paths are not included in the provided input.

## 4. Severity interpretation

This behaves like an ordinary Moderate or Low-like local DoS issue. The realistic impact is driver initialization failure, kernel Oops, or system crash depending on kernel configuration and error handling. The theoretical paranoid case is a local user indirectly causing a GPU reinit crash, but there is no evidence of memory corruption beyond a NULL dereference and no plausible privilege escalation primitive. This should not be treated as an Important-class kernel vulnerability based on the provided patch.

## 5. One-sentence report phrase

A NULL pointer dereference in AMDGPU device initialization can occur when SDMA is disabled and `buffer_funcs_ring` is not initialized, causing a local denial of service during driver initialization or reinitialization.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

This can be auto-closed for urgent security triage because it is a configuration dependent NULL dereference with local or administrative reachability, no network exposure, and no supported confidentiality, integrity, or privilege escalation primitive.

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

Patch: drm/amdgpu: fix NULL pointer issue buffer funcs [ Upstream
Commit: 29fd416e0e08aa6d5a97fd313749d08d83de0826
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=29fd416e0e08aa6d5a97fd313749d08d83de0826

Changed files:
  drivers/gpu/drm/amd/amdgpu/amdgpu_device.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=29fd416e0e08aa6d5a97fd313749d08d83de0826

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

The original Linux kernel CVE announcement for CVE-2025-71294 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2025-71294

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:N/I:N/A:H
  The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 5.5

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: 0
  Paranoid ActionableScore: 2

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: LOW
KPANIC detected for this report: NO
Published priority for this report (same as in Subject): LOW

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).