[CVE-2026-74385][MODERATE 7.0] nvmet-tcp: check return value of nvmet_tcp_set_queue_sock [ Upstream

[CVE-2026-74385][MODERATE 7.0] nvmet-tcp: check return value of nvmet_tcp_set_queue_sock [ Upstream

[AL-KERNEL]

CVE: CVE-2026-74385
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: nvmet-tcp: check return value of nvmet_tcp_set_queue_sock [ Upstream
Commit: cba2ee57fd302727aea7d41e9d9cd0969f5df0fb
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=cba2ee57fd302727aea7d41e9d9cd0969f5df0fb
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74385
Analysis date: Sun, 16 Aug 2026 02:52:37 -0400
ActionableScore: 5
ActionableScore lower bound: 3
Actionable bucket: Actionable Moderate at minimum
Manual review required: YES

Summary:
A remote NVMe/TCP initiator with access to the target listener may trigger queue and socket resource leakage during TLS handshake failure handling, causing a potential denial of service without evidence of memory corruption or privilege escalation.

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

The original Linux kernel CVE announcement for CVE-2026-74385 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74385

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 7.0
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-2026-74385	MODERATE	CHECK WITH IMPACT FROM ORIG NN IMPORTANT	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:H';CWE-252;*CWE-772;CWE-404;**CWE-400;Other CVSS 'AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.3';DESCR 'nvmet tcp can leak queue and socket resources after a TLS handshake because nvmet_tcp_tls_handshake_done ignored failures from nvmet_tcp_set_queue_sock. If the socket is no longer in TCP_ESTABLISHED state, the socket callbacks may not be installed and cleanup may not happen correctly. For the CVSS the PR:N is used because an attacker does not need privileges on the target beyond reachability to the NVMe/TCP target listener. The vector is treated as AV:A because NVMe/TCP targets are normally deployed on isolated storage or data center networks rather than the public Internet. Impact is denial of service through resource exhaustion, with no evidence of information disclosure or privilege escalation from the patch context.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 4)	YES	REMOTE SIMPLEFIX NVME LEAK NETWORK LINUS  LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5	YES	NO	checked

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

ActionableScore=5
ActionableScoreLower=3

## 1. ActionableScore

* Conservative score: 3
* Paranoid score: 5
* Final recommended bucket: **Actionable Moderate at minimum**::

## 2. Signal breakdown

Conservative signals:

* Remote reachable / network-triggerable: +2. The affected path is in nvmet-tcp TLS connection handling and can be reached by a remote NVMe/TCP host that can connect to the target listener.
* Availability impact realistic: +1. Ignoring nvmet_tcp_set_queue_sock() failure can leak queue and socket resources, enabling resource exhaustion over repeated attempts.
* Hard or unreliable race / special timing required: -1. The failure depends on nvmet_tcp_set_queue_sock() failing, for example because the socket is no longer TCP_ESTABLISHED at handshake completion.
* Rare AND difficult-to-reach subsystem/configuration: -1. This requires NVMe/TCP target with TLS handshake upcall enabled and reachable, which is common in storage environments but not a default general-purpose host exposure.
* Important filesystem/storage path: +1. The bug affects NVMe target transport resource management, which is important for storage service availability.

Paranoid additional interpretation:

* Reliable kernel crash / strong DoS: +1. If an attacker can repeatedly drive TLS handshakes into this failure state, leaked queue and socket resources can accumulate into a practical target-side DoS.
* The timing penalty is not applied in the paranoid score because active connection close or state manipulation around TLS completion may be repeatable by a reachable initiator.

No memory corruption, UAF, double-free, OOB write, info leak, or privilege escalation primitive is supported by the patch.

## 3. Reachability analysis

A remote host with network access to the NVMe/TCP target port can potentially trigger the affected path during TLS handshake processing. No local account on the target is required, so this is PR:N in CVSS-style terms. The realistic exposure is usually adjacent or internal, because NVMe/TCP targets are normally deployed on isolated storage or data-center networks rather than the public Internet. Namespaces and containers do not materially reduce the attacker privilege requirement if the target listener is reachable over the network.

Call-site confidence: high. The patch directly shows the failing call in nvmet_tcp_tls_handshake_done() and the corrected cleanup path via nvmet_tcp_schedule_release_queue().

## 4. Severity interpretation

This behaves like an actionable Moderate resource-exhaustion issue, not an Important memory-corruption issue. The realistic impact is denial of service through leaked queue and socket resources after failed TLS handshake completion. The paranoid score is higher because the affected code is network-facing in NVMe/TCP deployments and resource leakage in a storage target can become operationally significant, but there is no evidence of confidentiality impact, integrity impact, or privilege escalation.

## 5. One-sentence report phrase

A remote NVMe/TCP initiator with access to the target listener may trigger queue and socket resource leakage during TLS handshake failure handling, causing a potential denial of service without evidence of memory corruption or privilege escalation.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

Reason: the issue is network-reachable in NVMe/TCP target deployments and affects storage service availability, even though the primitive is resource leakage rather than memory corruption.

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

Patch: nvmet-tcp: check return value of nvmet_tcp_set_queue_sock [ Upstream
Commit: cba2ee57fd302727aea7d41e9d9cd0969f5df0fb
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=cba2ee57fd302727aea7d41e9d9cd0969f5df0fb

Changed files:
  drivers/nvme/target/tcp.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=cba2ee57fd302727aea7d41e9d9cd0969f5df0fb

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

The original Linux kernel CVE announcement for CVE-2026-74385 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74385

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:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
  The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 5.3

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: 3
  Paranoid ActionableScore: 5

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 7.0

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).