CVE-2025-39994

CVE Details

Release Date:	2025-10-15
Impact:	Moderate	What is this?

Description

In the Linux kernel, the following vulnerability has been resolved: media: tuner: xc5000: Fix use-after-free in xc5000_release The original code uses cancel_delayed_work() in xc5000_release(), which does not guarantee that the delayed work item timer_sleep has fully completed if it was already running. This leads to use-after-free scenarios where xc5000_release() may free the xc5000_priv while timer_sleep is still active and attempts to dereference the xc5000_priv. A typical race condition is illustrated below: CPU 0 (release thread) | CPU 1 (delayed work callback) xc5000_release() | xc5000_do_timer_sleep() cancel_delayed_work() | hybrid_tuner_release_state(priv) | kfree(priv) | | priv = container_of() // UAF Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure that the timer_sleep is properly canceled before the xc5000_priv memory is deallocated. A deadlock concern was considered: xc5000_release() is called in a process context and is not holding any locks that the timer_sleep work item might also need. Therefore, the use of the _sync() variant is safe here. This bug was initially identified through static analysis. [hverkuil: fix typo in Subject: tunner -> tuner]

See more information about CVE-2025-39994 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	7.0
Vector String:	CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Version:	3.1
Attack Vector:	Local
Attack Complexity:	High
Privileges Required:	Low
User Interaction:	None
Scope:	Unchanged
Confidentiality Impact:	High
Integrity Impact:	High
Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 7 (kernel-uek)	ELSA-2025-28049	2025-12-12
Oracle Linux version 8 (kernel-uek)	ELSA-2025-28048	2025-12-12
Oracle Linux version 8 (kernel-uek)	ELSA-2025-28049	2025-12-12
Oracle Linux version 9 (kernel-uek)	ELSA-2025-28048	2025-12-12