CVE-2025-39994
What it is
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]
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account, but needs a user to act. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 7.3 HIGH (CVSS).
- Fix: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Record status
- Deferred
Attack profile CVSS 3.1 · 7.3
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2025-39994.md and follow it. Check whether this project is affected by CVE-2025-39994. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
References
- https://git.kernel.org/stable/c/3f876cd47ed8bca1e28d68435845949f51f90703
- https://git.kernel.org/stable/c/40b7a19f321e65789612ebaca966472055dab48c
- https://git.kernel.org/stable/c/4266f012806fc18e46da4a04d130df59a4946f93
- https://git.kernel.org/stable/c/71ed8b81a4906cb785966910f39cf7f5ad60a69e
- https://git.kernel.org/stable/c/9a00de20ed8ba90888479749b87bc1532cded4ce
- https://git.kernel.org/stable/c/bc4ffd962ce16a154c44c68853b9d93f5b6fc4b8
- https://git.kernel.org/stable/c/df0303b4839520b84d9367c2fad65b13650a4d42
- https://git.kernel.org/stable/c/e2f5eaafc0306a76fb1cb760aae804b065b8a341
- https://git.kernel.org/stable/c/effb1c19583bca7022fa641a70766de45c6d41ac