[CVE-2026-80919][MODERATE REGULAR] drm/amdgpu: fix recursive ww_mutex acquire in amdgpu_devcoredump_format [ Upstream

[CVE-2026-80919][MODERATE REGULAR] drm/amdgpu: fix recursive ww_mutex acquire in amdgpu_devcoredump_format [ Upstream

[AL-KERNEL]

CVE: CVE-2026-80919
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: drm/amdgpu: fix recursive ww_mutex acquire in amdgpu_devcoredump_format [ Upstream
Commit: 4e9b4dee0777ec9c835a4746e2d30382dd9d1044
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4e9b4dee0777ec9c835a4746e2d30382dd9d1044
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80919
Analysis date: Wed, 09 Sep 2026 12:55:18 -0400
ActionableScore: 4
ActionableScore lower bound: 3
Actionable bucket: Borderline / manual review recommended
Manual review required: YES

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-80919 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80919

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 REGULAR
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-2026-80919	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-80919 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-667;*CWE-833;*CWE-772;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.5';DESCR 'A local GPU user can trigger a denial of service in the amdgpu devcoredump path after a hung job because amdgpu_devcoredump_format() may lock the VM root PD reservation and then reserve an IB BO that shares the same dma_resv. This creates a recursive reservation_ww_class_mutex acquire without a ww_acquire_ctx and can become a real self-deadlock for always-valid BOs. For the CVSS the PR:L is used because reliable triggering normally requires local access to the DRM render device or another local context able to submit GPU work that reaches the devcoredump path. The issue is not network reachable and is not a privilege escalation based on the patch context. Impact is denial of service through a stuck GPU recovery or devcoredump worker and possible kernel log flooding, with only secondary resource leakage from a BO refcount leak on an error path.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline / manual review recommended (with actual score 4)  SKIP CVE-2026-80919 UNKNOWN SKIP No affected files built, so skip this CVE NO  - - unknown 	MAYBE	LOCK DEADLOCK INIT LEAK HARDWARE DEBUGFS MEMORY  DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH	-	-	checked

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

ActionableScore=4
ActionableScoreLower=3
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=NO
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=RECOMMENDED
AutoDowngradeAllowed=YES

1. ActionableScore

* Raw conservative score: 3
* Conservative score: 3. No floor or cap applied.
* Raw paranoid score: 4
* Paranoid score: 4. No floor or cap applied.
* Final recommended bucket: **Borderline / manual review recommended**::

2. Signal breakdown

Conservative positive signals:

* +1 Reliable local DoS: the commit establishes a real self-deadlock when the IB BO shares the same dma_resv as the VM root PD, causing the devcoredump path to block.
* +1 Local below-host-admin reachability: normal DRM render-node users can submit GPU workloads that may reach hung-job and devcoredump handling. This does not require host-admin-equivalent privilege in typical DRM render deployments.
* +1 Concrete persistent kernel resource/reference leak: the commit explicitly says the old per-IB amdgpu_bo_reserve()/amdgpu_bo_unref() handling included a BO refcount leak on the amdgpu_bo_reserve() failure path.

Paranoid additional signal:

* +1 Additional availability degradation: with amdgpu.gpu_recovery=0, the timeout handler can refire every about 2 seconds and repeatedly emit lockdep splats, potentially flooding the kernel ring buffer. This is counted only in the paranoid score because it depends on that recovery configuration.

Negative signals:

* No -2 host-admin penalty: host-admin-equivalent privilege is not positively established for the complete trigger.
* No -1 rare hardware penalty: AMDGPU is hardware-specific but not rare or physical-only in the sense required by the scoring rules.
* No -1 hard race penalty: this is a locking/order bug in a devcoredump path, not a narrow timing race.

Non-awarded signals:

* RealUAF not awarded: the patch establishes recursive ww_mutex locking, self-deadlock, and a BO refcount leak, not use-after-free.
* Class A corruption not awarded: no controlled reclaim, arbitrary write, directed kernel write, callback control, or object replacement is shown.
* Structured stale-object leverage not awarded: there is no stale structured object use after lifetime end.
* Concrete repeated release/refcount mutation not awarded: the patch mentions a refcount leak, not a second put/release through a potentially dangling reference.
* C/I impact not awarded: no confidentiality or integrity primitive is established.
* Extra crash availability not double-counted: the main deadlock DoS is counted once.
* Remote reachability not awarded: the path is local GPU/DRM workload handling, not packet or network input.

3. Reachability analysis

The evaluated attacker is a local GPU user or local process with access to the AMDGPU DRM render interface. Such a user can submit GPU work and may be able to trigger a hung job that causes amdgpu_devcoredump_deferred_work to format the devcoredump and dump IB contents.

Host administrator privilege is not positively required for normal render-node GPU job submission, so HostAdminRequired=NO. This is not a namespace-scoped capability issue, so NamespaceScopedPrivilege=NO. No network path is involved.

The exact trigger also depends on AMDGPU being present, devcoredump of a hung job being reached, and an IB BO sharing dma_resv with the VM root PD, described by the commit as the always-valid case. This is a specific driver/runtime condition, but not enough to classify the issue as rare hardware or host-admin-only.

Race repeatability is not the main factor. The vulnerable condition is a recursive reservation_ww_class_mutex acquire without one shared ww_acquire_ctx, which can deterministically self-deadlock under the described BO sharing condition.

4. Primitive and severity interpretation

The exact primitive is a local locking/lifetime-management correctness bug in the AMDGPU devcoredump IB dumping path. The code locks the VM root PD reservation and then separately reserves an IB BO that may share the same dma_resv. Without a common ww_acquire_ctx, this can re-acquire the same ww_mutex and block forever.

This is not active structured UAF and not fixed stale storage UAF. It is primarily a Class C DoS/invalid locking behavior. The demonstrated consequence is self-deadlock in the devcoredump path, stuck GPU recovery/devcoredump work, possible repeated warning output, and a secondary BO refcount leak on an error path.

Speculative privilege escalation is not supported by the patch. There is no evidence of memory corruption beyond a leak, no arbitrary read/write, no controlled reclaim, no callback hijack, and no authorization bypass.

ImportantCandidate=NO because the established primitive is DoS/resource leak only and does not leave an unresolved kernel corruption primitive of Important-grade quality. ManualReview=RECOMMENDED because local DRM reachability and operational impact in GPU recovery paths are worth checking for the affected product, but AutoDowngradeAllowed=YES because no meaningful unresolved exploitation primitive beyond DoS is established.

Likely operational severity is Borderline to Actionable Moderate depending on how exposed local GPU workloads are and whether GPU recovery/devcoredump behavior is important for the deployment.

5. One-sentence report phrase

A local AMDGPU user may trigger a devcoredump IB dumping path that recursively acquires the same reservation_ww_class_mutex, causing a self-deadlock and denial of service without evidence of memory corruption or privilege escalation.

6. Manual review recommendation

MANUAL CHECK RECOMMENDED

Reason: the issue is local DoS in a common GPU driver path and below-host-admin DRM reachability is plausible, but the patch supports deadlock and refcount leak only, not UAF, arbitrary corruption, information disclosure, or privilege escalation.

7. Call-site confidence

Call-site confidence: medium

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

Patch: drm/amdgpu: fix recursive ww_mutex acquire in amdgpu_devcoredump_format [ Upstream
Commit: 4e9b4dee0777ec9c835a4746e2d30382dd9d1044
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4e9b4dee0777ec9c835a4746e2d30382dd9d1044

Changed files:
  drivers/gpu/drm/amd/amdgpu/amdgpu_dev_coredump.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=4e9b4dee0777ec9c835a4746e2d30382dd9d1044

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

The original Linux kernel CVE announcement for CVE-2026-80919 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80919

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: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: 3
  Paranoid ActionableScore: 4

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 REGULAR

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).