[CVE-2026-53060][LOW] dm cache metadata: fix memory leak on metadata abort retry [ Upstream

[CVE-2026-53060][LOW] dm cache metadata: fix memory leak on metadata abort retry [ Upstream

[AL-KERNEL]

CVE: CVE-2026-53060
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: dm cache metadata: fix memory leak on metadata abort retry [ Upstream
Commit: 14f60e957f34f95a626caec76a8fae88cf4c397f
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=14f60e957f34f95a626caec76a8fae88cf4c397f
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53060
Analysis date: Fri, 26 Jun 2026 07:15:25 -0400
ActionableScore: 2
ActionableScore lower bound: 0
Actionable bucket: Ordinary Moderate / Low-like, autoclose candidate
Manual review required: YES

Summary:
A missing cleanup path in dm_cache_metadata_abort can leak a temporary block manager during metadata abort retry after a failed write lock, causing a privileged local device-mapper resource leak with possible cumulative DoS but no supported memory corruption or privilege escalation primitive.

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

The original Linux kernel CVE announcement for CVE-2026-53060 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53060

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: YES

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

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

CVE-2026-53060	LOW	CHECK	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-401;*CWE-772;**CWE-400;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.5';DESCR 'dm_cache_metadata_abort can leak a temporary block manager when metadata abort retry reaches a failed write lock path after the metadata becomes read-only or fail_io is set. The issue is a local device mapper control plane resource leak rather than a packet or remote storage data path bug. For the CVSS the PR:L is used for the paranoid case because some environments may delegate device mapper control to a storage service or reduced capability admin account, while a normal host usually requires CAP_SYS_ADMIN. The issue is not network reachable. Impact is denial of service through cumulative kernel memory exhaustion if the abort and reload sequence can be repeated. No direct confidentiality or integrity impact is supported because the primitive is a memory leak without UAF, OOB access, or arbitrary write.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like, autoclose candidate (with actual score 1) 	MAYBE	DEADLOCK DISK RACE LEAK HARDWARE LINUS  DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	-	-	checked

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

ActionableScore=2
ActionableScoreLower=0

## 1. ActionableScore

* Conservative score: 0
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate / Low-like, autoclose candidate**::

## 2. Signal breakdown

Conservative scoring:

* Important filesystem/storage path: +1. The bug is in dm-cache metadata abort handling.
* Requires admin/root/CAP_SYS_ADMIN in typical deployments: -2. Reproducing the issue requires dmsetup table reload, suspend, resume, and cache device management.
* Rare and difficult-to-reach configuration: -1. The reliable reproducer needs dm-cache, metadata I/O failure or read-only metadata state, and repeated abort/reload behavior.
* Clamp to 0 because the total is negative.

Paranoid scoring:

* Availability impact realistic: +1. Repeated retries can leak kernel memory and could theoretically lead to resource exhaustion.
* Important filesystem/storage path: +1. The affected code is in device-mapper cache metadata management.
* No memory corruption signal. The patch fixes a missing cleanup path for a temporary block manager, not UAF, OOB access, double free, or arbitrary write.
* No confidentiality or integrity signal. There is no demonstrated disclosure, overwrite, metadata corruption, or privilege boundary bypass.

## 3. Reachability analysis

The bug is locally reachable through device-mapper cache management operations. In normal deployments, creating dm-cache devices, reloading tables, suspending and resuming targets, and forcing metadata error states require CAP_SYS_ADMIN or equivalent storage-management privileges.

Namespaces and containers usually do not make this reachable unless the container or service is explicitly delegated access to host device-mapper control. A reduced-capability storage service could make the paranoid PR interpretation more relevant, but this is not a normal unprivileged user path.

The path is not network reachable. It is not in a packet-processing or remote storage protocol parser. Triggering requires a specific dm-cache setup and metadata failure or read-only state.

## 4. Severity interpretation

This behaves like an ordinary Moderate or Low-like resource leak rather than an Important-class kernel vulnerability. The realistic impact is cumulative memory loss from repeated privileged control-plane operations.

Theoretical worst case is local DoS through sustained kernel memory exhaustion. The patch and call path do not support privilege escalation, memory corruption, information disclosure, page-cache corruption, or filesystem metadata corruption. The leak appears small per operation and requires privileged orchestration, so it should not be treated as actionable Moderate unless a deployment delegates device-mapper control to less trusted users.

## 5. One-sentence report phrase

A missing cleanup path in dm_cache_metadata_abort can leak a temporary block manager during metadata abort retry after a failed write lock, causing a privileged local device-mapper resource leak with possible cumulative DoS but no supported memory corruption or privilege escalation primitive.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED. NO MANUAL CHECK REQUIRED COULD BE AUTOCLOSED.

Reason: this is a privileged local resource leak with no memory corruption, no network reachability, no security-boundary bypass, and only cumulative availability impact under special dm-cache metadata failure conditions.

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

Patch: dm cache metadata: fix memory leak on metadata abort retry [ Upstream
Commit: 14f60e957f34f95a626caec76a8fae88cf4c397f
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=14f60e957f34f95a626caec76a8fae88cf4c397f

Changed files:
  drivers/md/dm-cache-metadata.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=14f60e957f34f95a626caec76a8fae88cf4c397f

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

The original Linux kernel CVE announcement for CVE-2026-53060 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53060

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:L/PR:H/UI:N/S:U/C:N/I:N/A:L
  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: 0
  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).