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.
References
Configurations
Configuration 1 (hide)
|
History
25 Nov 2025, 17:45
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Linux linux Kernel
Linux |
|
| CWE | CWE-416 | |
| References | () https://git.kernel.org/stable/c/3d4df408ba9bad2b205c7fb8afc1836a6a4ca88a - Patch | |
| References | () https://git.kernel.org/stable/c/5858448a6c65d8ee3f8600570d3ce19febcb33be - Patch | |
| References | () https://git.kernel.org/stable/c/e59a52e429e13df3feb34f4853a8e36d121ed937 - Patch | |
| References | () https://git.kernel.org/stable/c/fe546f5c50fc474daca6bee72caa7ab68a74c33d - Patch | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
Information
Published : 2025-09-05 18:15
Updated : 2025-11-25 17:45
NVD link : CVE-2025-39721
Mitre link : CVE-2025-39721
CVE.ORG link : CVE-2025-39721
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-416
Use After Free