GHSA-GHGH-R6C5-CGX8
Vulnerability from github – Published: 2025-10-15 09:30 – Updated: 2026-07-30 06:32In 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": [],
"aliases": [
"CVE-2025-39994"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-10-15T08:15:37Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: tuner: xc5000: Fix use-after-free in xc5000_release\n\nThe original code uses cancel_delayed_work() in xc5000_release(), which\ndoes not guarantee that the delayed work item timer_sleep has fully\ncompleted if it was already running. This leads to use-after-free scenarios\nwhere xc5000_release() may free the xc5000_priv while timer_sleep is still\nactive and attempts to dereference the xc5000_priv.\n\nA typical race condition is illustrated below:\n\nCPU 0 (release thread) | CPU 1 (delayed work callback)\nxc5000_release() | xc5000_do_timer_sleep()\n cancel_delayed_work() |\n hybrid_tuner_release_state(priv) |\n kfree(priv) |\n | priv = container_of() // UAF\n\nReplace cancel_delayed_work() with cancel_delayed_work_sync() to ensure\nthat the timer_sleep is properly canceled before the xc5000_priv memory\nis deallocated.\n\nA deadlock concern was considered: xc5000_release() is called in a process\ncontext and is not holding any locks that the timer_sleep work item might\nalso need. Therefore, the use of the _sync() variant is safe here.\n\nThis bug was initially identified through static analysis.\n\n[hverkuil: fix typo in Subject: tunner -\u003e tuner]",
"id": "GHSA-ghgh-r6c5-cgx8",
"modified": "2026-07-30T06:32:12Z",
"published": "2025-10-15T09:30:17Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-39994"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3f876cd47ed8bca1e28d68435845949f51f90703"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/40b7a19f321e65789612ebaca966472055dab48c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4266f012806fc18e46da4a04d130df59a4946f93"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/71ed8b81a4906cb785966910f39cf7f5ad60a69e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9a00de20ed8ba90888479749b87bc1532cded4ce"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/bc4ffd962ce16a154c44c68853b9d93f5b6fc4b8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/df0303b4839520b84d9367c2fad65b13650a4d42"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e2f5eaafc0306a76fb1cb760aae804b065b8a341"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/effb1c19583bca7022fa641a70766de45c6d41ac"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.