CVE-2025-39994: Linux kernel · media: tuner: xc5000: Fix use-after-free in xc5000_release
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.3 High · fixed in 5.15.0-1110.119~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 15:59 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1110.119~20.04.1, 5.15.0-1100.109~20.04.1, 5.15.0-1100.107~20.04.2 +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| linux-aws | Affected
| Fixed in
|
AI-suggested
A fix is available that replaces cancel_delayed_work() with cancel_delayed_work_sync() in the xc5000_release() function to properly cancel delayed work before freeing memory.
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]
References
- nvd.nist.gov/vuln/detail/CVE-2025-39994 (opens in a new tab)
- git.kernel.org/stable/c/3f876cd47ed8bca1e28d68435845949f51f90703 (opens in a new tab)
- git.kernel.org/stable/c/40b7a19f321e65789612ebaca966472055dab48c (opens in a new tab)
- git.kernel.org/stable/c/4266f012806fc18e46da4a04d130df59a4946f93 (opens in a new tab)
- git.kernel.org/stable/c/71ed8b81a4906cb785966910f39cf7f5ad60a69e (opens in a new tab)
- git.kernel.org/stable/c/9a00de20ed8ba90888479749b87bc1532cded4ce (opens in a new tab)
- git.kernel.org/stable/c/bc4ffd962ce16a154c44c68853b9d93f5b6fc4b8 (opens in a new tab)
- git.kernel.org/stable/c/df0303b4839520b84d9367c2fad65b13650a4d42 (opens in a new tab)
- git.kernel.org/stable/c/e2f5eaafc0306a76fb1cb760aae804b065b8a341 (opens in a new tab)
- git.kernel.org/stable/c/effb1c19583bca7022fa641a70766de45c6d41ac (opens in a new tab)
- ubuntu.com/security/CVE-2025-39994 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-39994 (opens in a new tab)
- git.kernel.org/linus/40b7a19f321e65789612ebaca966472055dab48c (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8034-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8034-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-6 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-7 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-8 (opens in a new tab)
- ubuntu.com/security/notices/USN-8095-1 (opens in a new tab)