[CVE-2025-71293][MODERATE 7.0] drm/amdgpu/ras: Move ras data alloc before bad page check [ Upstream

[CVE-2025-71293][MODERATE 7.0] drm/amdgpu/ras: Move ras data alloc before bad page check [ Upstream

[AL-KERNEL]

CVE: CVE-2025-71293
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: drm/amdgpu/ras: Move ras data alloc before bad page check [ Upstream
Commit: 0b7f78caeffa51a1afa521c284e863ec3b5a36df
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0b7f78caeffa51a1afa521c284e863ec3b5a36df
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2025-71293
Analysis date: Sat, 01 Aug 2026 12:54:04 -0400
ActionableScore: 5
ActionableScore lower bound: 3
Actionable bucket: Actionable Moderate at minimum
Manual review required: NO

Summary:
AMDGPU RAS bad-page restore can skip allocation when EEPROM contains only invalid bad-page entries, allowing a local sysfs read to trigger a NULL pointer dereference and kernel crash, with a weak additional concern from negative `space_left` accounting.

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

The original Linux kernel CVE announcement for CVE-2025-71293 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2025-71293

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: NO

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

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

CVE-2025-71293	MODERATE	CHECK WITH IMPACT FROM ORIG NN NONE	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H';**CWE-476;CWE-191;*CWE-787;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.8';DESCR 'AMDGPU RAS bad page restore can leave RAS error handler data without allocated bad page storage when EEPROM contains only invalid bad page address entries. A local user reading the RAS bad pages sysfs file can then hit a NULL pointer dereference in amdgpu_ras_sysfs_badpages_read and crash the kernel. For the CVSS the PR:L is used because the trigger is a local sysfs read by a user or process with access to the DRM device sysfs node, not full administrator control. The issue is not network reachable and requires an AMDGPU RAS environment with a rare invalid EEPROM bad page state. Impact is at least local denial of service via kernel crash. Worst case impact may include limited confidentiality or integrity impact because the negative space_left accounting could weaken allocation bounds, but the patch does not show a reliable arbitrary write or UAF primitive.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 4)  SKIP CVE-2025-71293  SKIP No affected files built, so skip this CVE NO  - - unknown 	MAYBE	OOB DANGER NULLPTR NOMEMCHK KERNEL_PANIC_PLUS_UAF HARDWARE  INCREASED_FROM_LOW_BASED_ON_REQUIREMANUALCHECK DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5	-	-	checked

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

ActionableScore=5
ActionableScoreLower=3

## 1. ActionableScore

* Conservative score: 3
* Paranoid score: 5
* Final recommended bucket: **Actionable Moderate at minimum**

## 2. Signal breakdown

Conservative signals:

* Local unprivileged trigger: +1
  The observed crash is triggered by reading the AMDGPU RAS badpages sysfs file via `cat`, assuming the sysfs node is readable by a local user or service account.
* Firmware-mediated external influence: +1
  The bad state depends on EEPROM bad-page entries containing only invalid addresses, so the trigger requires a device or firmware-fed precondition rather than purely attacker-created kernel state.
* Reliable kernel crash / strong DoS: +1
  The commit includes a concrete NULL pointer dereference in `amdgpu_ras_sysfs_badpages_read()` with an Oops trace.

Paranoid additional signals:

* Memory corruption, weak/indirect corruption candidate: +1
  The NULL dereference itself is DoS-only, but the negative `space_left` accounting suggests a broken allocation/count invariant around `data->bps`, `data->count`, and `data->space_left`.
* Privileged kernel/device-management corruption path: +1
  The bug affects AMDGPU RAS bad-page restore state, which is firmware-fed device-management metadata in a trusted kernel driver path.

Subtract / limiting factors:

* Rare hardware / configuration condition: -1
  The issue requires AMDGPU RAS plus a rare EEPROM state containing only invalid bad-page address entries.
* No strong LPE primitive: 0
  The patch does not show UAF reclaim, attacker-controlled overwrite, type confusion, callback control, refcount takeover, or arbitrary write.

## 3. Reachability analysis

A local user or local process can trigger the visible failure by reading the RAS badpages sysfs file after the driver has restored bad-page data from the problematic EEPROM state. This is not network reachable. Containers and namespaces generally do not improve reachability unless the AMDGPU sysfs nodes or DRM device-management files are exposed into the container. The path is not broadly default-exposed on all Linux systems because it depends on AMDGPU hardware, RAS support, and a rare invalid EEPROM bad-page table condition.

Call-site confidence: medium. The crash call path is shown in the trace, but the full surrounding allocation and sysfs read logic is not included.

## 4. Severity interpretation

This behaves primarily like a local DoS caused by a NULL pointer dereference in a device-specific sysfs read path. The negative `space_left` accounting makes the bug worth manual review because it indicates a broken buffer/accounting invariant, but the provided patch does not demonstrate a practical privilege escalation primitive. Conservative handling is borderline Moderate. Paranoid handling is Actionable Moderate because firmware-fed RAS metadata plus negative allocation accounting could hide a limited corruption sink.

## 5. One-sentence report phrase

AMDGPU RAS bad-page restore can skip allocation when EEPROM contains only invalid bad-page entries, allowing a local sysfs read to trigger a NULL pointer dereference and kernel crash, with a weak additional concern from negative `space_left` accounting.

## 6. Manual review recommendation

MANUAL CHECK RECOMMENDED

Manual review is recommended because the demonstrated impact is a kernel crash, but the negative `space_left` accounting and skipped allocation in a firmware-fed driver path make this more than a trivial NULL dereference cleanup.

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

Patch: drm/amdgpu/ras: Move ras data alloc before bad page check [ Upstream
Commit: 0b7f78caeffa51a1afa521c284e863ec3b5a36df
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0b7f78caeffa51a1afa521c284e863ec3b5a36df

Changed files:
  drivers/gpu/drm/amd/amdgpu/amdgpu_ras.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=0b7f78caeffa51a1afa521c284e863ec3b5a36df

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

The original Linux kernel CVE announcement for CVE-2025-71293 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2025-71293

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:H/PR:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H
  The Best / paranoid CVSS score: 5.8

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: 5

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).