* [CVE-2026-98326][LOW] wifi: mac80211: mesh: release the channel if start fails [ Upstream
@ 2026-10-09 5:49 21% AL-KERNEL
0 siblings, 0 replies; 1+ results
From: AL-KERNEL @ 2026-10-09 5:49 UTC (permalink / raw)
To: kernel-cve
CVE: CVE-2026-98326
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: wifi: mac80211: mesh: release the channel if start fails [ Upstream
Commit: f0afcec2129c166e61821d6ae097061155f01b12
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f0afcec2129c166e61821d6ae097061155f01b12
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98326
Analysis date: Fri, 09 Oct 2026 01:49:41 -0400
ActionableScore: 2
ActionableScore lower bound: unknown
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-2026-98326 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98326
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-2026-98326 LOW https://www.kernelcve.org/list/?q=CVE-2026-98326 CHECK WITH IMPACT FROM ORIG NN MODERATE | AEGIS IMPACT LOW AEGIS_AS=0 LEGACY=LOW RESULT=SAME (legacy and Aegis reconciliation agree; DECISION: both 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-404;CWE-459;*CWE-772;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.7';DESCR 'A failed mac80211 mesh startup can leave the assigned channel context attached because ieee80211_join_mesh returns the error without releasing the channel. Later interface or hardware removal can attempt to unassign that context after the interface has already been removed from the driver, causing a driver state warning and an incomplete teardown. For the CVSS the PR:L value in the paranoid score applies when limited network administration rights are delegated to a container, service account, or local user. Normal systems typically require CAP_NET_ADMIN and therefore correspond to PR:H in the base score. The issue is not directly network reachable because it requires local control plane operations to join a mesh and remove the affected interface. The demonstrated impact is limited availability loss for the interface. A host crash is plausible mainly when panic_on_warn is enabled or when the invalid teardown causes a wider driver failure. No UAF, OOB access, information leak, or write primitive is established by the affected path.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2) MAYBE REMOTE DANGER SYZBOT DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 - - checked
======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================
ActionableScore=2
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=NO
ManualReview=NO
AutoDowngradeAllowed=YES
1. ActionableScore
* Raw conservative score: 2.
* Conservative score: 2.
* Raw paranoid score: 2.
* Paranoid score: 2.
* No floor or cap was applied.
* Final recommended bucket: **Ordinary Moderate**::
2. Signal breakdown
* +1 Concrete resource retention. `ieee80211_join_mesh()` acquires a channel context but fails to release it when `ieee80211_start_mesh()` returns an error.
* +1 Limited availability impact. The retained assignment causes invalid channel-context cleanup during later interface or hardware removal and reaches a driver-state warning.
* +0 for the WARN. `WARN_ON` is not independently scored as a reliable host crash. A panic under `panic_on_warn` does not justify a paranoid bonus by itself.
* No negative privilege penalty was applied because the complete capability and namespace requirements are not established by the supplied evidence.
* No UAF, repeated release, refcount mutation, OOB access, controlled overwrite, arbitrary write, disclosure, or authorization bypass is established.
* No remote-reachability point was awarded because the path is reached through local mesh configuration and teardown rather than received wireless traffic.
* B5-R does not apply. There is no heap OOB write, retry-accumulated index, or later consumption of OOB-corrupted state.
3. Reachability analysis
The initial operation is a local mac80211 control-plane request to join a mesh. It normally involves network-administration authority, but the supplied patch does not establish whether every required stage, including inducing startup failure and removing the interface or simulated radio, requires host-admin-equivalent privilege.
The trace involves `mac80211_hwsim` and network-namespace teardown, but this alone does not prove that the complete trigger is available through an attacker-created namespace. Therefore, both host-admin and namespace-scoped reachability remain unknown. No special physical hardware is required for the demonstrated hwsim path. This is an ordered error and cleanup sequence, not a timing race.
4. Primitive and severity interpretation
The exact primitive is an unbalanced channel-context acquisition followed by delayed cleanup from an invalid driver state. It is not a stale post-lifetime object use, heap corruption, or repeated lifetime mutation. The later operation attempts to unassign a still-retained context after the interface has been removed from the driver, producing a warning and incomplete teardown.
This is CLASS_C invalid-state and resource-management behavior. The demonstrated consequence is limited disruption of interface or hardware teardown. Host panic is only a configuration-dependent possibility, and privilege escalation or memory corruption is unsupported.
`ImportantCandidate=NO` because no exploitation primitive remains beyond resource retention and invalid teardown. `AutoDowngradeAllowed=YES` because there is no unresolved corruption, ownership-boundary violation, authorization bypass, or security-relevant stale-object leverage.
5. One-sentence report phrase
A failed mac80211 mesh startup leaves its channel context assigned, causing invalid cleanup and a driver warning during later interface removal, with no established UAF, OOB write, information disclosure, or privilege-escalation primitive.
6. Manual review recommendation
NO MANUAL CHECK NEEDED
The issue is a constrained resource-cleanup defect with a demonstrated warning and device-interface teardown impact, while the supplied B5-R profile is not applicable.
7. Call-site confidence
Call-site confidence: high
======================================================================
UPSTREAM PATCH SUMMARY
======================================================================
Patch: wifi: mac80211: mesh: release the channel if start fails [ Upstream
Commit: f0afcec2129c166e61821d6ae097061155f01b12
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f0afcec2129c166e61821d6ae097061155f01b12
Changed files:
net/mac80211/driver-ops.c
net/mac80211/cfg.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=f0afcec2129c166e61821d6ae097061155f01b12
======================================================================
DETAILED REPORT METHODOLOGY
======================================================================
The original Linux kernel CVE announcement for CVE-2026-98326 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98326
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: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: unknown
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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