[CVE-2026-74523][MODERATE REGULAR] qede: sync udp_tunnel ports outside qede_lock in the recovery path [ Upstream

[CVE-2026-74523][MODERATE REGULAR] qede: sync udp_tunnel ports outside qede_lock in the recovery path [ Upstream

[AL-KERNEL]

CVE: CVE-2026-74523
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: qede: sync udp_tunnel ports outside qede_lock in the recovery path [ Upstream
Commit: e382a4efeeae6555b95d9ff336cf3094ee7d336b
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e382a4efeeae6555b95d9ff336cf3094ee7d336b
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74523
Analysis date: Sat, 15 Aug 2026 11:12:36 -0400
ActionableScore: 3
ActionableScore lower bound: 2
Actionable bucket: Borderline manual review recommended / Actionable Moderate at minimum
Manual review required: YES

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-74523 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74523

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: YES

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

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

CVE-2026-74523	MODERATE	CHECK WITH IMPACT FROM ORIG NN 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:H';CWE-667;*CWE-833;**CWE-400;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.3';DESCR 'A qede recovery path can deadlock when a TX timeout occurs on a qede NIC with VXLAN or GENEVE tunnel ports configured. The recovery worker holds rtnl_lock and qede_lock, then calls udp_tunnel_nic_reset_ntf which synchronously calls back into qede_udp_tunnel_sync and tries to take qede_lock again in the same task. This wedges the kworker while rtnl_lock is still held, so later rtnetlink users such as ip, ovs-vswitchd, lldpad, IPv6 addrconf, and sshd can block indefinitely even while the node still answers ping. For the CVSS the PR:N is used in the paranoid score because an adjacent attacker might only need traffic reachability to a qede based tunnel endpoint if the TX timeout can be induced without local credentials. In the typical base scenario PR:H is more realistic because reliable triggering depends on local administrative control of tunnel configuration or recovery conditions. Impact is denial of service through a wedged network control plane, with no evidence of memory corruption or privilege escalation.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline manual review recommended / Actionable Moderate at minimum (with actual score 3)	YES	REMOTE DEADLOCK DANGER NETWORK HARDWARE IPV6  DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH	NO	NO	checked

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

ActionableScore=3
ActionableScoreLower=2

1. ActionableScore
* Conservative score: 2
* Paranoid score: 3
* Final recommended bucket: **Borderline manual review recommended / Actionable Moderate at minimum**::

2. Signal breakdown
* Reliable kernel crash / strong DoS: +1. The bug can wedge the recovery kworker while holding rtnl_lock, blocking later rtnetlink users indefinitely.
* Availability impact realistic: +1. The impact is system-wide network control-plane denial of service, not just a single failed command.
* Remote reachable / network-triggerable: +2 in paranoid only. This is defensible only if network traffic can induce the qede TX timeout on an already configured VXLAN/GENEVE endpoint.
* Hard or unreliable race / special condition: -1. Triggering requires qede hardware, configured tunnel ports, and a TX timeout/recovery path.
* Rare hardware/configuration dependency: -1. The issue is specific to qede NICs with VXLAN/GENEVE tunnel offload configuration.
* No memory corruption signal. The patch fixes lock ordering and callback placement, not UAF, OOB, double free, type confusion, or refcount misuse.
* No privilege escalation signal. The demonstrated primitive is persistent DoS through rtnl_lock deadlock.

3. Reachability analysis
A local administrator can configure the relevant qede VXLAN/GENEVE tunnel state and can likely force recovery conditions more reliably. A remote or adjacent attacker may only be relevant in the paranoid interpretation, where traffic to an already configured tunnel endpoint can contribute to or trigger the TX timeout. Namespaces do not substantially lower privileges for configuring the affected hardware path, but they may increase impact because many host and container networking operations depend on rtnetlink. The path is not default for all systems because it requires qede hardware and tunnel configuration, but it is realistic in some data-center deployments.

4. Severity interpretation
This behaves like an actionable DoS issue rather than an Important memory-corruption vulnerability. The practical impact can be severe because rtnl_lock remains held and many networking control-plane tasks can block forever while the node still responds to ping. However, the patch does not support confidentiality impact, integrity impact, privilege escalation, or arbitrary code execution. The paranoid score is higher only for the possibility of adjacent traffic influencing the TX timeout trigger.

5. One-sentence report phrase
A qede recovery-path lock-ordering bug can deadlock the recovery worker while holding rtnl_lock after a TX timeout on a VXLAN/GENEVE configured NIC, causing persistent host-wide network control-plane DoS without evidence of memory corruption or privilege escalation.

6. Manual review recommendation
MANUAL CHECK RECOMMENDED.
The issue is DoS-only by primitive, but production impact can be broad because rtnetlink is wedged system-wide, and the real triggerability by adjacent traffic versus only privileged local recovery control is environment-dependent.

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

Patch: qede: sync udp_tunnel ports outside qede_lock in the recovery path [ Upstream
Commit: e382a4efeeae6555b95d9ff336cf3094ee7d336b
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e382a4efeeae6555b95d9ff336cf3094ee7d336b

Changed files:
  drivers/net/ethernet/qlogic/qede/qede_main.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=e382a4efeeae6555b95d9ff336cf3094ee7d336b

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

The original Linux kernel CVE announcement for CVE-2026-74523 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74523

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:H
  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: 2
  Paranoid ActionableScore: 3

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).