* [CVE-2026-89886][LOW] media: intel/ipu6: fix async notifier cleanup leak on parse error
@ 2026-09-16 11:11 21% AL-KERNEL
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From: AL-KERNEL @ 2026-09-16 11:11 UTC (permalink / raw)
To: kernel-cve
CVE: CVE-2026-89886
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: media: intel/ipu6: fix async notifier cleanup leak on parse error
Commit: dd5943aedbe4d7eb46158cb35078257733ac48b6
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=dd5943aedbe4d7eb46158cb35078257733ac48b6
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89886
Analysis date: Wed, 16 Sep 2026 07:11:45 -0400
ActionableScore: 2
ActionableScore lower bound: 1
Actionable bucket: Ordinary Moderate
Manual review required: NO
Summary:
No one-sentence report phrase was found.
======================================================================
ABOUT THIS REPORT
======================================================================
The original Linux kernel CVE announcement for CVE-2026-89886 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89886
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-2026-89886 LOW https://www.kernelcve.org/list/?q=CVE-2026-89886 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:H/UI:N/S:U/C:N/I:N/A:H';*CWE-401;*CWE-772;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.4';DESCR 'The Intel IPU6 notifier initialization path can leak previously allocated v4l2_async_connection objects when endpoint parsing or remote subdevice addition fails after part of the notifier waiting list has already been populated. Repeated probe or bind and unbind failures could accumulate leaked kernel memory and may eventually cause resource exhaustion, although a single failure is expected to have limited availability impact. For the CVSS the PR:H value is used because reliable repeated triggering normally requires administrative control over device probing, driver binding, or firmware graph configuration. The issue is not network reachable. There is no UAF, out of bounds access, stale pointer traversal, or demonstrated memory corruption primitive, so the supported impact is resource exhaustion and denial of service only.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2) SKIP CVE-2026-89886 UNKNOWN SKIP The Fixes patch not applied yet, so unlikely that actual: url YES NO NO unknown MAYBE SIMPLEFIX LEAK ERRORPATH HARDWARE - - checked
======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================
ActionableScore=2
ActionableScoreLower=1
PrimitiveClass=NONE
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=NO
AutoDowngradeAllowed=YES
1. ActionableScore
* Raw conservative score: 1
* Conservative score: 1
* Raw paranoid score: 2
* Paranoid score: 2
* No floor or cap was applied.
* Final recommended bucket: **Ordinary Moderate**::
2. Signal breakdown
Conservative signals:
* +1 Concrete persistent kernel resource/reference leak. Connections successfully added to the notifier waiting list are permanently lost when a later endpoint parse or add operation fails.
* No negative privilege penalty. Administrative control appears likely for reliable repeated triggering, but host-admin-equivalent privilege is not positively established by the supplied code.
* No hardware penalty. Intel IPU6 hardware is required, but the evidence does not establish that it is sufficiently rare to justify a deduction.
Additional paranoid signal:
* +1 Potential cumulative resource exhaustion. Repeated failed initialization attempts can allocate and abandon additional connection objects, making progressive kernel-memory consumption technically defensible.
Important non-awarded signals:
* No UAF, stale post-lifetime access, double release, OOB access, or memory overwrite is established.
* No reliable kernel crash or immediate host-wide exhaustion is demonstrated.
* No confidentiality, integrity, authorization-bypass, or privilege-escalation primitive is established.
* No remote reachability or attacker-controlled payload or target is established.
* No additional availability point is awarded beyond the paranoid accumulation scenario.
3. Reachability analysis
The leak occurs while probing and initializing an Intel IPU6 media device with firmware-described endpoints. A parse failure or failure to add a remote subdevice is required after at least one connection has already been added.
An ordinary local user trigger is not established. Reliable repetition would likely require control over driver probing, binding, or the firmware graph, but the supplied evidence does not prove the exact privilege checks for the complete sequence. HostAdminRequired is therefore UNKNOWN rather than YES.
The operation concerns a host PCI media device and firmware-node topology rather than a namespace-scoped interface. No attacker-created namespace capability can perform the complete operation. Prior presence of compatible Intel IPU6 hardware and an endpoint configuration that fails partway through initialization is required. There is no race or timing requirement.
4. Primitive and severity interpretation
The exact primitive is a missing cleanup operation that leaks allocated v4l2_async_connection objects from the notifier waiting list. This is an ownership and resource-release defect, not a dangling-reference use. RealUAF is NO, and no repeated release or refcount mutation exists.
PrimitiveClass is NONE because the patch establishes only a resource leak and no corruption, authorization, ownership-boundary, or post-lifetime access primitive useful beyond resource consumption. The demonstrated consequence is persistent leakage per failed initialization. Eventual memory exhaustion is a defensible paranoid consequence if initialization failures can be repeated, but immediate host-wide denial of service is not established.
ImportantCandidate is NO because there is no Important-grade primitive or unresolved corruption leverage. AutoDowngradeAllowed is YES because the issue is limited to resource leakage, has no demonstrated security-boundary impact, and can be handled as a low-priority resource-management defect.
5. One-sentence report phrase
A missing notifier cleanup on the Intel IPU6 endpoint parse error path leaks previously allocated connection objects and may cause gradual kernel memory exhaustion if failed device initialization is repeatedly triggered.
6. Manual review recommendation
NO MANUAL CHECK NEEDED
The patch establishes a conventional initialization-error resource leak without UAF, memory corruption, network reachability, or a security-boundary primitive.
7. Call-site confidence
Call-site confidence: high
======================================================================
UPSTREAM PATCH SUMMARY
======================================================================
Patch: media: intel/ipu6: fix async notifier cleanup leak on parse error
Commit: dd5943aedbe4d7eb46158cb35078257733ac48b6
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=dd5943aedbe4d7eb46158cb35078257733ac48b6
Commit description:
isys_notifier_init() calls v4l2_async_nf_init() and then adds fwnode
remote subdevs in a loop with v4l2_async_nf_add_fwnode_remote(). If an
endpoint parse or add fails partway through the loop, it jumps to
err_parse and returns without calling v4l2_async_nf_cleanup(), leaking
every v4l2_async_connection already added to the notifier's waiting
list.
The register-failure path just below already cleans up correctly, and
the caller only tears the notifier down (isys_notifier_cleanup()) once
isys_notifier_init() has returned success. Clean up the notifier on the
parse error path too.
Fixes: f50c4ca ("media: intel/ipu6: add the main input system driver")
Cc: [email protected]
Assisted-by: Claude:claude-opus-4
Signed-off-by: Cong Nguyen <[email protected]>
Signed-off-by: Sakari Ailus <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Changed files:
drivers/media/pci/intel/ipu6/ipu6-isys.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=dd5943aedbe4d7eb46158cb35078257733ac48b6
======================================================================
DETAILED REPORT METHODOLOGY
======================================================================
The original Linux kernel CVE announcement for CVE-2026-89886 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89886
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:H/UI:N/S:U/C:N/I:N/A:L
The Best / paranoid CVSS vector: AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
The Best / paranoid CVSS score: 4.4
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 [email protected] (and both
send reply to CVE record itself too and see "reply" button below for howto reply).
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