[CVE-2026-68298][LOW] drm/xe/vm: Fix SVM leak on resv obj alloc failure in xe_vm_create() [ Upstream

[CVE-2026-68298][LOW] drm/xe/vm: Fix SVM leak on resv obj alloc failure in xe_vm_create() [ Upstream

[AL-KERNEL]

CVE: CVE-2026-68298
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: drm/xe/vm: Fix SVM leak on resv obj alloc failure in xe_vm_create() [ Upstream
Commit: 279339aa8bdcf9db40094cf2bcbd495c53dbe817
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=279339aa8bdcf9db40094cf2bcbd495c53dbe817
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68298
Analysis date: Mon, 10 Aug 2026 13:59:07 -0400
ActionableScore: 2
ActionableScore lower bound: 1
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
A resource leak in the drm/xe VM creation error path can leave gpusvm and pagemap resources unreleased after a reservation object allocation failure, allowing a local user with Xe DRM device access to cause gradual resource exhaustion and denial of service.

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

The original Linux kernel CVE announcement for CVE-2026-68298 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68298

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-2026-68298	LOW	CHECK WITH IMPACT FROM ORIG NN LOW	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';*CWE-401;*CWE-772;**CWE-400;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.7';DESCR 'A resource leak in the drm/xe VM creation error path can occur after xe_svm_init succeeds and drm_gpuvm_resv_object_alloc fails. Non fault mode VMs can leave gpusvm resources initialized, while fault mode VMs can also keep pagemap owner and pagemap references because the close path is not executed. For the CVSS the PR:L is used because a local process with access to the DRM Xe device or render node can normally reach VM creation interfaces, but reliable triggering also depends on hitting the allocation failure path. The issue is not network reachable and does not show a concrete UAF, OOB access, or arbitrary write primitive. Impact is denial of service through gradual resource exhaustion rather than privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 2)	YES	LEAK ERRORPATH HARDWARE 	YES	NO	checked

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

ActionableScore=2
ActionableScoreLower=1

## 1. ActionableScore

* Conservative score: 1
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate / Low-like**

## 2. Signal breakdown

Conservative:

* Local unprivileged trigger: +1. A local process with access to the Intel Xe DRM device or render node can reach VM creation paths in typical desktop or GPU compute deployments.
* Availability impact realistic: +1. Repeated triggering can leak gpusvm, pagemap owner, or pagemap references and may eventually cause resource exhaustion.
* Hard or unreliable condition: -1. The leak is on an error unwind path after `xe_svm_init()` succeeds and `drm_gpuvm_resv_object_alloc()` fails, so reliable triggering depends on a specific allocation failure condition.

Conservative total: 1

Paranoid:

* Local unprivileged trigger: +1. DRM render node access can be available to non-root users depending on device permissions.
* Availability impact realistic: +1. Sustained abuse could exhaust kernel or GPU VM related resources.
* Reliable strong DoS is not awarded separately. The patch describes leaks, not an immediate crash or direct panic path.
* No memory corruption signal. The patch fixes missing cleanup, with no UAF, OOB write, double free, type confusion, refcount takeover, arbitrary write, or page-cache corruption shown.
* No privilege escalation signal. There is no concrete primitive beyond resource leakage.
* Hard or unreliable condition: -1 would normally apply, but for the paranoid score it is effectively balanced by assuming the allocation failure path can be induced under memory pressure.

Paranoid total: 2

## 3. Reachability analysis

A local process that can open the Xe DRM device and create VMs can potentially reach the affected path. This is usually PR:L rather than PR:H because render nodes are commonly delegated to non-root desktop, compute, or container workloads, although exact reachability depends on device node permissions and group membership.

The issue is not network reachable. Namespaces or containers matter only if the Xe render device is passed through or exposed to the container. The path is hardware and driver dependent and also requires the specific reservation object allocation failure during VM creation, which makes reliable exploitation harder than ordinary ioctl-triggered crashes.

Call-site confidence: medium. The provided patch shows the cleanup path and the missing calls, but not the full ioctl entry path or allocation failure controllability.

## 4. Severity interpretation

This behaves like an ordinary Moderate or Low-like resource leak rather than an Important-class vulnerability. The realistic impact is local denial of service through gradual resource exhaustion. Theoretical severity is limited because the patch does not show a memory corruption primitive, stale pointer reuse, attacker-controlled reclaim, arbitrary write, information disclosure, or privilege escalation path.

## 5. One-sentence report phrase

A resource leak in the drm/xe VM creation error path can leave gpusvm and pagemap resources unreleased after a reservation object allocation failure, allowing a local user with Xe DRM device access to cause gradual resource exhaustion and denial of service.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

This can be processed as low-priority resource-leak triage unless product-specific policy exposes Xe render nodes broadly to untrusted users and resource exhaustion is considered operationally critical.

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

Patch: drm/xe/vm: Fix SVM leak on resv obj alloc failure in xe_vm_create() [ Upstream
Commit: 279339aa8bdcf9db40094cf2bcbd495c53dbe817
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=279339aa8bdcf9db40094cf2bcbd495c53dbe817

Changed files:
  drivers/gpu/drm/xe/xe_vm.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=279339aa8bdcf9db40094cf2bcbd495c53dbe817

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

The original Linux kernel CVE announcement for CVE-2026-68298 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68298

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:L
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 4.7

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: 1
  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).