CVE-2025-39994

Description

In the Linux kernel, the following vulnerability has been resolved:media: tuner: xc5000: Fix use-after-free in xc5000_releaseThe original code uses cancel_delayed_work() in xc5000_release(), whichdoes not guarantee that the delayed work item timer_sleep has fullycompleted if it was already running. This leads to use-after-free scenarioswhere xc5000_release() may free the xc5000_priv while timer_sleep is stillactive 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() // UAFReplace cancel_delayed_work() with cancel_delayed_work_sync() to ensurethat the timer_sleep is properly canceled before the xc5000_priv memoryis deallocated.A deadlock concern was considered: xc5000_release() is called in a processcontext and is not holding any locks that the timer_sleep work item mightalso 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]

Risk Information

Associated Vulnerability

Patch Details

References

https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234