[CVE-2026-64118][MODERATE 7.0] qed: fix double free in qed_cxt_tables_alloc() [ Upstream

[CVE-2026-64118][MODERATE 7.0] qed: fix double free in qed_cxt_tables_alloc() [ Upstream

[AL-KERNEL]

CVE: CVE-2026-64118
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: qed: fix double free in qed_cxt_tables_alloc() [ Upstream
Commit: 9fe030719bd083b766602692ee96c8c985798e3c
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9fe030719bd083b766602692ee96c8c985798e3c
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64118
Analysis date: Sun, 19 Jul 2026 17:20:44 -0400
ActionableScore: 5
ActionableScore lower bound: 2
Actionable bucket: Actionable Moderate at minimum
Manual review required: YES

Summary:
A double free in the qed driver CID bitmap allocation rollback path can occur when partial PF/VF bitmap allocation fails, leading to kernel memory corruption and likely local DoS, with only weak but review-worthy privilege-escalation concern due to the double-free primitive.

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

The original Linux kernel CVE announcement for CVE-2026-64118 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64118

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-2026-64118	MODERATE	CHECK WITH IMPACT FROM ORIG NN MODERATE	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H';CWE-415;*CWE-664;CWE-703;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '7';DESCR 'A double-free can occur in the qed driver error path when a later PF/VF CID bitmap allocation fails. qed_cid_map_alloc() frees previously allocated CID bitmap pointers on failure, and the outer cleanup path can later call qed_cid_map_free() and free the same pointers again. The realistic trigger is local and difficult because it depends on device specific qed initialization or recovery plus an allocation failure at the right point. For the CVSS the PR:L is used in the paranoid score to cover environments where a non-root local actor can influence memory pressure or delegated device recovery while the vulnerable driver path is exercised. Impact is at least local denial of service via kernel crash. In the worst defensible case, double-free memory corruption may allow confidentiality or integrity impact and should be reviewed manually.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 4)	YES	REMOTE DANGER SIMPLEFIX NETWORK HARDWARE LINUS  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5	NO	NO	checked

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

ActionableScore=5
ActionableScoreLower=2

## 1. ActionableScore

* Conservative score: 2
* Paranoid score: 5
* Final recommended bucket: **Actionable Moderate at minimum**::

## 2. Signal breakdown

Conservative signals:

* +2 Generic memory corruption, strong primitive: the patch fixes a confirmed double free of CID bitmap pointers.
* +1 Real lifetime corruption: previously freed bitmap pointers remained stored and could be freed again by a later cleanup path.
* +1 Reliable kernel crash / strong DoS: if the error path is reached, allocator double free is a realistic kernel crash condition.
* +1 Privileged kernel/device-management memory corruption path: the bug is in a NIC driver initialization / cleanup path.
* -2 Requires admin/root/device lifecycle control in typical deployments: reliable triggering normally requires driver probe, recovery, reset, or device-specific setup.
* -1 Hard or unreliable trigger: the failing allocation path needs a specific partial allocation failure and was not runtime reproduced.

Paranoid additions / interpretation:

* +1 Weak LPE concern: double free is real kernel memory corruption, but no attacker-controlled reclaim, overwrite target, or object replacement is shown.
* No remote-reachable score: this is not a packet receive path and no network-triggered path is shown.
* No strong LPE score: the patch does not demonstrate controlled reuse, arbitrary write, type confusion, callback control, or refcount takeover.

## 3. Reachability analysis

The realistic trigger is local and difficult. It depends on a QLogic qed device being initialized or recovered and on a later PF or VF CID bitmap allocation failing after earlier bitmaps were already allocated and freed during rollback. In typical deployments, controlling the driver lifecycle or reset path requires host administrative privileges, although a paranoid interpretation can consider reduced-privilege service accounts, delegated device management, or local memory pressure influencing allocation failure while the driver path is exercised. Namespaces do not appear to make this directly reachable by ordinary unprivileged container users unless device control is explicitly delegated. Call-site confidence: medium, because the commit describes the caller sequence clearly but the full surrounding allocation and recovery call graph is not included.

## 4. Severity interpretation

This is not an ordinary low-risk cleanup bug because the primitive is a confirmed double free in kernel memory management. Realistic exploitation is constrained by device-specific setup and an allocation-failure error path, so the conservative view is closer to low-end Moderate / borderline. The paranoid view is Actionable Moderate because double-free lifetime corruption can sometimes become more than DoS, but the current patch context does not justify treating it as a strong Important candidate without manual source review.

## 5. One-sentence report phrase

A double free in the qed driver CID bitmap allocation rollback path can occur when partial PF/VF bitmap allocation fails, leading to kernel memory corruption and likely local DoS, with only weak but review-worthy privilege-escalation concern due to the double-free primitive.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED.
Reason: confirmed kernel double free and lifetime corruption, even though the practical trigger is difficult and device-specific.

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

Patch: qed: fix double free in qed_cxt_tables_alloc() [ Upstream
Commit: 9fe030719bd083b766602692ee96c8c985798e3c
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9fe030719bd083b766602692ee96c8c985798e3c

Changed files:
  drivers/net/ethernet/qlogic/qed/qed_cxt.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=9fe030719bd083b766602692ee96c8c985798e3c

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

The original Linux kernel CVE announcement for CVE-2026-64118 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64118

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:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
  The Best / paranoid CVSS score: 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: 2
  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).