[CVE-2026-98293][MODERATE REGULAR] Bluetooth: ISO: Fix parent socket leak in iso_conn_ready() [ Upstream

[CVE-2026-98293][MODERATE REGULAR] Bluetooth: ISO: Fix parent socket leak in iso_conn_ready() [ Upstream

[AL-KERNEL]

CVE: CVE-2026-98293
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: Bluetooth: ISO: Fix parent socket leak in iso_conn_ready() [ Upstream
Commit: ea8a262662be62c095789924c11722ecbf40a4de
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ea8a262662be62c095789924c11722ecbf40a4de
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98293
Analysis date: Sat, 10 Oct 2026 22:26:55 -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-2026-98293 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98293

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: NO

A detailed explanation of the methodology and priority rules is included
at the end of this message.

======================================================================
AL-KERNEL CLASSIFICATION RESULT
======================================================================

CVE-2026-98293	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-98293 CHECK WITH IMPACT FROM ORIG NN IMPORTANT | AEGIS IMPACT MODERATE AEGIS_AS=1 LEGACY=MODERATE RESULT=SAME (legacy and Aegis reconciliation agree; DECISION: both MODERATE)	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L';*CWE-401;*CWE-772;BEST CVSS score: '3.1';DESCR 'A reference leak in the Bluetooth ISO connection path occurs when iso_get_sock returns a referenced parent socket and iso_sock_alloc then fails. The error path releases the socket lock but does not drop the reference, which can retain the parent socket and associated resources after they should be released. A nearby Bluetooth peer may initiate the connection processing, but exploitation also depends on a GFP_ATOMIC child socket allocation failure that the peer cannot normally control reliably. For the CVSS the PR:N value is used because no authenticated or local user privileges are required for a Bluetooth peer within radio range to reach the connection path. The attack vector is adjacent rather than Internet reachable. The demonstrated impact is limited resource retention with low availability impact. There is no supported UAF, out of bounds access, information disclosure, arbitrary write, or privilege escalation primitive. Reliable host wide resource exhaustion through repeated failures is not established.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2)	MAYBE	REMOTE SIMPLEFIX LEAK ERRORPATH NETWORK LINUS  LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4	-	-	checked

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

ActionableScore=2
ActionableScoreLower=1
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=NO
ManualReview=RECOMMENDED
AutoDowngradeAllowed=YES
RequiresHostUID0=UNKNOWN
AuthorizationDecisionBypass=NO
ProtectedResourceImpact=NONE
B4PendingReview=NO
B4PendingConfirmed=NO

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. `iso_get_sock()` acquires a reference to the parent socket, and the `iso_sock_alloc()` failure path loses that reference by returning without `sock_put()`.
* Total: 1.

Additional paranoid signal:

* +1 Firmware-mediated external influence. A nearby Bluetooth peer can influence connection processing through the Bluetooth controller, but local ISO/BIS setup and an allocation failure are still required.
* Total: 2.

Material non-awarded signals:

* No direct remote-reachability +2. The path requires an existing parent ISO socket and active BIS-related state, so attacker traffic alone is not shown to establish the complete path.
* No reliable crash or strong DoS point. The demonstrated result is one retained socket reference, not a panic or established host-wide exhaustion.
* No generic resource-exhaustion point. Repeatable accumulation and attacker control over `GFP_ATOMIC` allocation failure are not established.
* No UAF point. The missing `sock_put()` extends the parent lifetime rather than allowing post-free use.
* No repeated-release point. This is a missing release, not two lifetime mutations through the same potentially dangling reference.
* No confidentiality, integrity, authorization-bypass, OOB-write, controlled-reclaim, or privilege-escalation signal.
* B5-R, B3-PENDING, and B4-PENDING do not apply.

3. Reachability analysis

A local Bluetooth ISO user or service must first create the parent socket and establish the relevant ISO/BIS state. A nearby Bluetooth peer can plausibly influence the event that reaches `iso_conn_ready()`, but the leaking branch is entered only if `iso_sock_alloc(..., GFP_ATOMIC, ...)` fails.

The supplied evidence does not establish that an external peer can reliably force that allocation failure or repeat it enough to exhaust host resources. It also does not establish whether creating the required parent socket requires host-admin-equivalent privilege in the evaluated deployment. Therefore `HostAdminRequired` remains `UNKNOWN`.

No user-namespace or namespace-scoped capability chain is shown. Prior local Bluetooth configuration is required, but whether it must be provisioned by a separate privileged actor is unresolved. Bluetooth-capable hardware and ISO support are prerequisites. There is no race.

4. Primitive and severity interpretation

The exact primitive is a persistent parent-socket reference leak on an allocation-error path. `release_sock(parent)` releases the socket lock but does not drop the reference obtained by `iso_get_sock()`. The added `sock_put(parent)` restores the missing ownership release.

This is not stale storage, UAF, memory corruption, or a second refcount mutation through an expired object. The parent remains alive longer than intended. The demonstrated consequence is resource retention. Repeated host-wide exhaustion is only speculative because reliable control over both connection retries and atomic allocation failures is not established.

`PrimitiveClass=CLASS_C` reflects a constrained availability/resource-management defect. `ImportantCandidate=NO` because there is no corruption, security-boundary bypass, strong DoS, or demonstrated accumulation mechanism. `AutoDowngradeAllowed=YES` because no unresolved Important-preserving primitive remains.

5. One-sentence report phrase

A missing `sock_put()` after Bluetooth ISO child socket allocation failure leaks the referenced parent socket, but reliable repeated accumulation or host-wide resource exhaustion is not established.

6. Manual review recommendation

MANUAL CHECK RECOMMENDED

Confirm whether an untrusted nearby peer can repeatedly reach the allocation-failure branch and whether leaked parent sockets can accumulate under realistic memory pressure.

7. Call-site confidence

Call-site confidence: medium

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

Patch: Bluetooth: ISO: Fix parent socket leak in iso_conn_ready() [ Upstream
Commit: ea8a262662be62c095789924c11722ecbf40a4de
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ea8a262662be62c095789924c11722ecbf40a4de

Changed files:
  net/bluetooth/iso.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=ea8a262662be62c095789924c11722ecbf40a4de

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

The original Linux kernel CVE announcement for CVE-2026-98293 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98293

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: Not available
  The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
  The Best / paranoid CVSS score: 3.1

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: 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).