[CVE-2026-72059][LOW] net: wwan: t7xx: destroy DMA pool on CLDMA late init failure commit 2bd6f26d4ce1e87de4d736b1e8896daf3acf1c0e upstream.

[AL-KERNEL <alkernel@kernelcve.org>]

CVE: CVE-2026-72059
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: net: wwan: t7xx: destroy DMA pool on CLDMA late init failure commit 2bd6f26d4ce1e87de4d736b1e8896daf3acf1c0e upstream.
Commit: cef50f9f9045ff5e6a9d62c5110522df98fca645
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=cef50f9f9045ff5e6a9d62c5110522df98fca645
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72059
Analysis date: Sat, 15 Aug 2026 21:57:02 -0400
ActionableScore: 1
ActionableScore lower bound: 0
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
A missing dma_pool_destroy() in the t7xx WWAN CLDMA late init failure path can leak a DMA pool after ring initialization errors, causing possible resource exhaustion only after repeated privileged or firmware influenced initialization failures.

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

The original Linux kernel CVE announcement for CVE-2026-72059 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72059

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: NO

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-2026-72059	LOW	CHECK WITH IMPACT FROM ORIG NN LOW	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';*CWE-401;*CWE-772;**CWE-400;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.7';DESCR 'A DMA pool resource leak in the t7xx WWAN CLDMA late init path occurs because md_ctrl gpd_dmapool is created before TX and RX ring setup, but the failure path did not destroy it if ring initialization failed. A local attacker usually cannot trigger this through packet traffic. Practical triggering requires conditions that make driver initialization fail, such as device or firmware errors, fault injection, or privileged device management. For the CVSS the PR:L is used in the paranoid score because some environments may delegate modem or device reset control to a service account or container with reduced capabilities. The issue is not network reachable. Impact is denial of service only through gradual kernel memory resource leakage after repeated failed initialization attempts.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1)  SKIP CVE-2026-72059 UNKNOWN SKIP No affected files built, so skip this CVE NO  - - unknown 	MAYBE	SIMPLEFIX LEAK ERRORPATH NETWORK DMAorINTERRUPT LINUS MEMORY  DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	-	-	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=1
ActionableScoreLower=0

## 1. ActionableScore

* Conservative score: 0
* Paranoid score: 1
* Final recommended bucket: **Ordinary Moderate / Low-like**::

## 2. Signal breakdown

Conservative signals:

* Availability impact realistic: +1. The leaked DMA pool can accumulate only if CLDMA late initialization repeatedly fails.
* Requires admin/root/CAP_* in typical deployments: -2. Triggering usually requires driver load, device reset, reprobe, fault injection, or privileged WWAN device management.
* Rare AND difficult-to-reach subsystem/configuration: -1. This is a t7xx WWAN CLDMA driver failure path and requires specific hardware plus an initialization failure.

Conservative total is clamped to 0.

Paranoid signals:

* Firmware-mediated external influence: +1. Ring initialization failure may depend on modem firmware or device state, so external device behavior can influence reachability.
* Availability impact realistic: +1. Sustained repeated failures could leak enough DMA pool memory to cause resource pressure.
* Rare AND difficult-to-reach subsystem/configuration: -1. The affected path is hardware-specific and not a normal packet-processing path.

Paranoid total: 1.

Not awarded:

* No remote reachable signal. This is not triggered by network packets.
* No local unprivileged trigger. Ordinary users normally cannot force this init failure path.
* No memory corruption signal. The patch fixes a missing dma_pool_destroy() on an error path.
* No LPE signal. There is no UAF, OOB write, double free, stale callback, object confusion, or controlled overwrite.
* No strong DoS signal. The impact is gradual resource leakage, not an immediate reliable crash.

## 3. Reachability analysis

The bug is reachable during t7xx CLDMA late initialization if TX or RX ring setup fails after md_ctrl->gpd_dmapool has already been created. In typical deployments, only privileged users or system services can load, reset, reprobe, or otherwise manage the WWAN device. Namespace or container delegation could lower practical privileges if a service account or container root is allowed to control modem reset paths, but that is not the default assumption.

The path is not default-reachable through ordinary network traffic. It requires specific t7xx WWAN hardware and a failure during driver initialization or recovery. Realistic exploitation would require repeated failed init attempts or firmware/device behavior that consistently forces the error path.

## 4. Severity interpretation

This behaves like a Low-like or ordinary Moderate resource leak, not an actionable Moderate or Important kernel vulnerability. The theoretical worst case is resource exhaustion after repeated failures, but the patch does not show memory corruption, privilege escalation, information disclosure, or a reliable kernel crash primitive.

The issue should not be treated as Important. It is suitable for deferred handling unless the affected product exposes untrusted users to modem reset or driver reprobe controls.

## 5. One-sentence report phrase

A missing dma_pool_destroy() in the t7xx WWAN CLDMA late init failure path can leak a DMA pool after ring initialization errors, causing possible resource exhaustion only after repeated privileged or firmware influenced initialization failures.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

This is a DMA pool resource leak on a hardware-specific privileged initialization failure path, with no evidence of UAF, OOB access, privilege escalation, information disclosure, or network-triggerable attack surface.

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

Patch: net: wwan: t7xx: destroy DMA pool on CLDMA late init failure commit 2bd6f26d4ce1e87de4d736b1e8896daf3acf1c0e upstream.
Commit: cef50f9f9045ff5e6a9d62c5110522df98fca645
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=cef50f9f9045ff5e6a9d62c5110522df98fca645

Commit description:

t7xx_cldma_late_init() creates md_ctrl->gpd_dmapool before
initializing the TX and RX rings. If any ring initialization
fails, the error path frees the already initialized rings but
leaves the DMA pool allocated.

Destroy md_ctrl->gpd_dmapool on the late-init failure path
to avoid leaking the DMA pool.

Fixes: 39d439047f1d ("net: wwan: t7xx: Add control DMA interface")
Cc: stable@vger.kernel.org
Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
Reviewed-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
Link: https://patch.msgid.link/20260621031714.3605022-1-haoxiang_li2024@163.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat -rw-r--r-- drivers/net/wwan/t7xx/t7xx_hif_cldma.c 3

Changed files:
  drivers/net/wwan/t7xx/t7xx_hif_cldma.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=cef50f9f9045ff5e6a9d62c5110522df98fca645

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

The original Linux kernel CVE announcement for CVE-2026-72059 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72059

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:L
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 4.7

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: 0
  Paranoid ActionableScore: 1

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).