CVE-2025-39994: Linux

High severity, CVSS 7.3. EPSS: 0.2% chance of exploitation in the next 30 days.

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]

Affected products

• Linux Linux: from 3.16, before 5.4.301 (fixed in 5.4.301); from 5.5, before 5.10.246 (fixed in 5.10.246); from 5.11, before 5.15.195 (fixed in 5.15.195); from 5.16, before 6.1.156 (fixed in 6.1.156); from 6.2, before 6.6.111 (fixed in 6.6.111); from 6.7, before 6.12.51 (fixed in 6.12.51); …

Published 2025-10-15. Last modified 2026-07-30.