VDB-322956 · CVE-2025-39721 · Nessus 261633

Linux Kernel up to 6.6.102/6.12.43/6.16.3 qat_4xxx use after free

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6.6	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.6.102/6.12.43/6.16.3 and classified as critical. The impacted element is the function qat_4xxx. The manipulation results in use after free. This vulnerability is identified as CVE-2025-39721. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.6.102/6.12.43/6.16.3. Affected is the function qat_4xxx. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: crypto: qat - flush misc workqueue during device shutdown Repeated loading and unloading of a device specific QAT driver, for example qat_4xxx, in a tight loop can lead to a crash due to a use-after-free scenario. This occurs when a power management (PM) interrupt triggers just before the device-specific driver (e.g., qat_4xxx.ko) is unloaded, while the core driver (intel_qat.ko) remains loaded. Since the driver uses a shared workqueue (`qat_misc_wq`) across all devices and owned by intel_qat.ko, a deferred routine from the device-specific driver may still be pending in the queue. If this routine executes after the driver is unloaded, it can dereference freed memory, resulting in a page fault and kernel crash like the following: BUG: unable to handle page fault for address: ffa000002e50a01c #PF: supervisor read access in kernel mode RIP: 0010:pm_bh_handler+0x1d2/0x250 [intel_qat] Call Trace: pm_bh_handler+0x1d2/0x250 [intel_qat] process_one_work+0x171/0x340 worker_thread+0x277/0x3a0 kthread+0xf0/0x120 ret_from_fork+0x2d/0x50 To prevent this, flush the misc workqueue during device shutdown to ensure that all pending work items are completed before the driver is unloaded. Note: This approach may slightly increase shutdown latency if the workqueue contains jobs from other devices, but it ensures correctness and stability.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2025-39721 since 04/16/2025. The exploitability is told to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 02/09/2026).

The vulnerability scanner Nessus provides a plugin with the ID 261633 (Linux Distros Unpatched Vulnerability : CVE-2025-39721), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.103, 6.12.44, 6.16.4 or 6.17-rc1 eliminates this vulnerability. Applying the patch 5858448a6c65d8ee3f8600570d3ce19febcb33be/fe546f5c50fc474daca6bee72caa7ab68a74c33d/e59a52e429e13df3feb34f4853a8e36d121ed937/3d4df408ba9bad2b205c7fb8afc1836a6a4ca88a is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (261633) and CERT Bund (WID-SEC-2025-1988). Once again VulDB remains the best source for vulnerability data.

Affected

Debian Linux
Google Cloud Platform
Amazon Linux 2
Red Hat Enterprise Linux
Ubuntu Linux
SUSE Linux
Oracle Linux
NetApp FAS
NetApp AFF
NetApp ActiveIQ Unified Manager
SUSE openSUSE
RESF Rocky Linux
Open Source Linux Kernel
Microsoft Azure
Dell Secure Connect Gateway
IBM QRadar SIEM
IBM Security Verify Access
Dell NetWorker

Productinfo

Type

Operating System

Vendor

Linux

Name

Kernel

Version

License

open-source

Website

Vendor: https://www.kernel.org/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.8
VulDB Meta Temp Score: 6.6

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
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Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒