CVE-2025-39721

MEDIUM EPSS 3.2%
Published Sep 5, 20259mo ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Sep 5, 2025 9mo ago
Last Modified Jun 17, 2026 1w ago

Description

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.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
3.2% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-416 Use After Free Memory Safety

Affected Products 3

VendorProductVersionRange
linuxlinux_kernel*≥5.18  –  <6.6.103
linuxlinux_kernel*≥6.7  –  <6.12.44
linuxlinux_kernel*≥6.13  –  <6.16.4

References 5

  • git.kernel.org https://git.kernel.org/stable/c/3d4df408ba9bad2b205c7fb8afc1836a6a4ca88a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5858448a6c65d8ee3f8600570d3ce19febcb33be
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e59a52e429e13df3feb34f4853a8e36d121ed937
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/fa4c14a82747886d333d8baef0d26da86ba1ccf7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/fe546f5c50fc474daca6bee72caa7ab68a74c33d
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/3d4df408ba9bad2b205c7fb8afc1836a6a4ca88a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5858448a6c65d8ee3f8600570d3ce19febcb33be
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e59a52e429e13df3feb34f4853a8e36d121ed937
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/fa4c14a82747886d333d8baef0d26da86ba1ccf7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/fe546f5c50fc474daca6bee72caa7ab68a74c33d
    Patch