* [CVE-2026-80884][LOW] ntb: Store original DMA address for future release [ Upstream
@ 2026-09-04 20:58 21% AL-KERNEL
0 siblings, 0 replies; 1+ results
From: AL-KERNEL @ 2026-09-04 20:58 UTC (permalink / raw)
To: kernel-cve
CVE: CVE-2026-80884
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: ntb: Store original DMA address for future release [ Upstream
Commit: 10662aafce4acd52278c942d0a5b3993594017b9
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=10662aafce4acd52278c942d0a5b3993594017b9
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80884
Analysis date: Fri, 04 Sep 2026 16:58:32 -0400
ActionableScore: 2
ActionableScore lower bound: 1
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: YES
Summary:
No one-sentence report phrase was found.
======================================================================
ABOUT THIS REPORT
======================================================================
The original Linux kernel CVE announcement for CVE-2026-80884 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80884
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: YES
A detailed explanation of the methodology and priority rules is included
at the end of this message.
======================================================================
AL-KERNEL CLASSIFICATION RESULT
======================================================================
CVE-2026-80884 LOW https://www.kernelcve.org/list/?q=CVE-2026-80884 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-763;CWE-404;*CWE-401;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.4';DESCR 'The NTB transport code could pass a modified DMA address to dma_free_coherent instead of the original DMA handle returned by the allocation API. This violates the DMA API contract and can lead to an invalid DMA release, DMA debug warnings, leaked DMA or IOMMU resources, or device level denial of service during repeated init and teardown cycles. For the CVSS the PR:H is used because reliable triggering normally requires administrative control over the NTB driver or hardware lifecycle. The issue is not network reachable and is tied to local device management paths. Impact is primarily availability loss, with no clear UAF, OOB write, information leak, or privilege escalation primitive visible from the patch context.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 2) YES OOB SIMPLEFIX DMAorINTERRUPT MEMORY DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 NO NO checked
======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================
ActionableScore=2
ActionableScoreLower=1
1. ActionableScore
* Conservative score: 1
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate / Low-like**::
2. Signal breakdown
* Privileged kernel/device-management DMA-adjacent path: +1. The bug is in NTB transport DMA buffer lifecycle handling and passes a modified DMA handle to dma_free_coherent.
* Availability impact plausible: +1 in the paranoid case. Repeated init teardown or reset cycles could cause DMA debug warnings, leaked DMA or IOMMU resources, or NTB device-level DoS.
* Requires admin/root/device-management privileges: -2. Reliable triggering normally requires control over NTB driver lifecycle, reset, load, unload, or device setup.
* Rare hardware/device-specific exposure: -1. NTB is not a broadly exposed default subsystem and requires suitable hardware or topology.
* No strong memory corruption primitive. The patch does not show UAF, OOB write, attacker-controlled overwrite, type confusion, arbitrary write, or callback control.
* No confidentiality or integrity signal. The visible consequence is invalid DMA release or resource lifecycle mismatch, not data disclosure or unauthorized modification.
3. Reachability analysis
The likely trigger is local and privileged through NTB device setup, driver initialization, teardown, reset, or error handling. A normal unprivileged local user is not expected to reach this path directly. Containers or namespaces do not normally lower this to PR:L unless NTB device management is explicitly delegated, which would be unusual. The path is not network reachable. External NTB peer behavior may influence device state in some deployments, but the supplied patch does not support scoring it as remotely triggerable.
4. Severity interpretation
This behaves like a low-end Moderate or Low-like device lifecycle bug. The realistic impact is availability degradation through invalid DMA free behavior, DMA debug complaints, resource leaks, or device failure during repeated lifecycle operations. Theoretical memory corruption is not well supported because the patch only preserves the exact DMA handle required by the DMA API and does not demonstrate attacker-controlled memory reuse, overwrite, or stale object access. The issue should not be treated as Important based on the provided evidence.
5. One-sentence report phrase
The NTB transport driver could pass a modified DMA handle to dma_free_coherent instead of the original allocation handle, causing invalid DMA release behavior and possible device-level denial of service in privileged local device-management paths.
6. Manual review recommendation
NO MANUAL CHECK NEEDED. NO MANUAL CHECK REQUIRED COULD BE AUTOCLOSED.
Reason: this is a privileged, hardware-specific DMA lifecycle correctness fix with no demonstrated UAF, OOB write, information leak, privilege escalation path, or network reachability.
======================================================================
UPSTREAM PATCH SUMMARY
======================================================================
Patch: ntb: Store original DMA address for future release [ Upstream
Commit: 10662aafce4acd52278c942d0a5b3993594017b9
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=10662aafce4acd52278c942d0a5b3993594017b9
Changed files:
drivers/ntb/ntb_transport.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=10662aafce4acd52278c942d0a5b3993594017b9
======================================================================
DETAILED REPORT METHODOLOGY
======================================================================
The original Linux kernel CVE announcement for CVE-2026-80884 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80884
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: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).
^ permalink raw reply [relevance 21%]
Results 1-1 of 1 | reverse | sort options + mbox downloads above
-- links below jump to the message on this page --
2026-09-04 20:58 21% [CVE-2026-80884][LOW] ntb: Store original DMA address for future release [ Upstream AL-KERNEL
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox