[CVE-2026-68313][LOW] tipc: fix infinite loop in __tipc_nl_compat_dumpit [ Upstream

[CVE-2026-68313][LOW] tipc: fix infinite loop in __tipc_nl_compat_dumpit [ Upstream

[AL-KERNEL]

CVE: CVE-2026-68313
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: tipc: fix infinite loop in __tipc_nl_compat_dumpit [ Upstream
Commit: f9c669d9f4cac832fe31193cdbc24c6a9d99398b
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f9c669d9f4cac832fe31193cdbc24c6a9d99398b
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68313
Analysis date: Mon, 10 Aug 2026 18:59:31 -0400
ActionableScore: 2
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-68313 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68313

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-2026-68313	LOW	CHECK WITH IMPACT FROM ORIG NN IMPORTANT	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H';*CWE-835;**CWE-400;CWE-667;BEST CVSS score: '5.5';DESCR 'A local denial of service can occur in the TIPC netlink compatibility dump path because __tipc_nl_compat_dumpit uses the dumpit return value as the loop length. If the callback returns a negative errno, the while condition remains true and the loop can run indefinitely while genl_mutex is held. This can starve other generic netlink users and leave waiting tasks in D state. For the CVSS the PR:L value is used for the paranoid score because a local process with access to the TIPC netlink compatibility path or delegated network administration capability can be enough in some deployments. The issue is not directly network reachable and does not show a memory corruption primitive. Impact is denial of service only through mutex starvation and system responsiveness degradation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 2)	YES	DANGER SIMPLEFIX TIPC LINUS SYZBOT  LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	NO	NO	checked

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

ActionableScore=2

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

2. Signal breakdown
* Local trigger: +1. The issue is reachable through a local TIPC netlink compatibility control path.
* Reliable kernel DoS: +1. A negative dumpit return can cause an infinite loop while holding genl_mutex, starving other generic netlink users and leaving tasks waiting in D state.
* No memory corruption: +0. The patch only checks len < 0 and exits on error. There is no UAF, OOB access, double free, type confusion, stale pointer, arbitrary write, or info leak shown.
* No privilege escalation signal: +0. The bug is an infinite loop and mutex starvation issue, not a corruption primitive.
* No remote reachability: +0. The affected path is a local netlink control path, not packet processing.
* TIPC compat path is not a broad default exposure: no positive broad exposure signal.

3. Reachability analysis
A local process that can reach the affected TIPC netlink compatibility dump path may trigger the bug if cmd->dumpit returns a negative errno. In typical deployments, some TIPC configuration paths may require network administration privileges, but the previous CVSS interpretation using PR:L is defensible for triage because delegated netadmin or namespace setups can reduce the practical privilege barrier. This is not directly network-triggerable. Exploitation conditions are realistic for DoS if the interface is reachable, but the impact remains limited to local availability degradation.

4. Severity interpretation
This behaves like an ordinary Moderate local denial-of-service issue. The failure mode is an infinite loop with genl_mutex held, causing generic netlink starvation and D-state waiters. There is no demonstrated theoretical or practical memory corruption primitive, and no evidence supporting confidentiality impact, integrity impact, or privilege escalation.

5. One-sentence report phrase
A local DoS in the TIPC netlink compatibility dump path can occur when a negative dumpit errno is treated as a nonzero loop length, causing an infinite loop while holding genl_mutex and starving other generic netlink users.

6. Manual review recommendation
NO MANUAL CHECK NEEDED. The patch and commit message show a DoS-only infinite-loop bug with no memory corruption, no remote attack surface, and no plausible privilege-escalation primitive.

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

Patch: tipc: fix infinite loop in __tipc_nl_compat_dumpit [ Upstream
Commit: f9c669d9f4cac832fe31193cdbc24c6a9d99398b
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f9c669d9f4cac832fe31193cdbc24c6a9d99398b

Changed files:
  net/tipc/netlink_compat.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=f9c669d9f4cac832fe31193cdbc24c6a9d99398b

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

The original Linux kernel CVE announcement for CVE-2026-68313 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68313

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:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 5.5

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 alexanjelausa@gmail.com (and both
send reply to CVE record itself too and see "reply" button below for howto reply).