[CVE-2026-46162][MODERATE 7.0] ice: fix double free in ice_sf_eth_activate() error path

[CVE-2026-46162][MODERATE 7.0] ice: fix double free in ice_sf_eth_activate() error path

[AL-KERNEL]

CVE: CVE-2026-46162
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: ice: fix double free in ice_sf_eth_activate() error path
Commit: 2ca30340b5028ddc3f17086a538feeff06167b1b
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2ca30340b5028ddc3f17086a538feeff06167b1b
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46162
Analysis date: Thu, 28 May 2026 11:39:46 -0400
ActionableScore: 7
ActionableScore lower bound: 4
Actionable bucket: Strong Important candidate / Actionable Moderate at minimum
Manual review required: YES

Summary:
`ice_sf_eth_activate()` can double free `sf_dev` when `auxiliary_device_add()` fails, because `auxiliary_device_uninit()` already releases the object but the old error path also called `kfree()`.

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

The original Linux kernel CVE announcement for CVE-2026-46162 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46162

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.

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AL-KERNEL CLASSIFICATION RESULT
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CVE-2026-46162	MODERATE	CHECK	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-416;*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 'ice_sf_eth_activate could double free sf_dev when auxiliary_device_add failed. auxiliary_device_uninit invokes the device release callback, which already frees sf_dev, but the old error path then fell through to kfree(sf_dev) again. For the CVSS the PR:L is used for the paranoid score when reduced privilege users, container root, or delegated device management can trigger subfunction activation paths, although the base case is closer to PR:H because this is normally privileged device management. The issue is not network reachable by packets. Impact is at least local denial of service via kernel crash, and worst case may allow confidentiality or integrity impact because double-free is a kernel memory corruption primitive.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Strong Important candidate / Actionable Moderate at minimum (with actual score 6) 	MAYBE	REMOTE DANGER SIMPLEFIX ERRORPATH NETWORK HARDWARE KPANIC  KPANIC DECREASED_TO_MODERATE70_BASED_ON_ACTIONABLESCORELOWERTHAN7	-	-	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=7
ActionableScoreLower=4

## 1. ActionableScore

* Conservative score: 4
* Paranoid score: 7
* Final recommended bucket: **Strong Important candidate / Actionable Moderate at minimum**::

## 2. Signal breakdown

Conservative signals:

* Generic memory corruption: +2. The bug is a real double free of `sf_dev`.
* Real lifetime corruption: +1. Ownership is transferred to the auxiliary device release callback, then the same object is freed again.
* Reliable kernel crash / strong DoS: +1. Double free can crash or corrupt allocator state.
* Requires admin/device-management control in typical deployments: -2. Subfunction activation normally requires privileged devlink/device management.
* Constrained trigger: -1. The double free is on an `auxiliary_device_add()` failure path, not the normal success path.
* Privileged device-management memory corruption path: +1. The corruption occurs in an Intel Ethernet subfunction activation path.

Paranoid additional signals:

* Local delegated trigger: +1. Reduced-privilege root, container root, or delegated device-management users may be able to trigger subfunction activation in some environments.
* Weak to strong LPE concern: +2. Double free is a kernel memory corruption primitive, though exploitability depends on controlling the failure and allocator reuse.

## 3. Reachability analysis

The trigger is local and tied to Intel ice subfunction activation. A normal unprivileged user cannot usually reach this path. It normally requires devlink or device-management privileges.

Containers matter if device management is delegated to container root or reduced-capability service accounts. The bug is not reachable by network packets alone, and practical exploitation requires `auxiliary_device_add()` to fail after ownership has reached the release-callback path.

## 4. Severity interpretation

Conservatively this is a privileged local DoS/error-path bug. Paranoid triage raises it to a Strong Important candidate because the primitive is a real kernel double free, not merely a NULL dereference or warning.

No concrete arbitrary write or LPE chain is shown, so the high score reflects manual-review sensitivity and the double-free class, not proven privilege escalation.

## 5. One-sentence report phrase

`ice_sf_eth_activate()` can double free `sf_dev` when `auxiliary_device_add()` fails, because `auxiliary_device_uninit()` already releases the object but the old error path also called `kfree()`.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

This is a kernel double free in a device-management error path. Review should focus on whether untrusted or delegated users can trigger ice subfunction activation and force the auxiliary-device failure path.

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

Patch: ice: fix double free in ice_sf_eth_activate() error path
Commit: 2ca30340b5028ddc3f17086a538feeff06167b1b
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2ca30340b5028ddc3f17086a538feeff06167b1b

Commit description:

When auxiliary_device_add() fails, ice_sf_eth_activate() jumps to
aux_dev_uninit and calls auxiliary_device_uninit(&sf_dev->adev).

The device release callback ice_sf_dev_release() frees sf_dev, but
the current error path falls through to sf_dev_free and calls
kfree(sf_dev) again, causing a double free.

Keep kfree(sf_dev) for the auxiliary_device_init() failure path, but
avoid falling through to sf_dev_free after auxiliary_device_uninit().

Fixes: 13acc5c ("ice: subfunction activation and base devlink ops")
Cc: stable@vger.kernel.org
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20260416-iwl-net-submission-2026-04-14-v2-3-686c33c9828d@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/net/ethernet/intel/ice/ice_sf_eth.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=2ca30340b5028ddc3f17086a538feeff06167b1b

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

The original Linux kernel CVE announcement for CVE-2026-46162 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46162

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: 4
  Paranoid ActionableScore: 7

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: YES
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).