CVE-2025-39994
Full vulnerability record from the local CVENow database.
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]
Severity
HIGH
CVSS score
7.3
(v3.1)
Vulnerability status
Deferred
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2025-10-15 08:15:37.567000
Last modified
2026-10-19 21:10:00.160000
View original CVE JSON
{
"id": "CVE-2025-39994",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2025-10-15T08:15:37.567",
"lastModified": "2026-10-19T21:10:00.160",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "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 -> tuner]"
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nmedia: tuner: xc5000: Corrige uso después de liberación en xc5000_release\n\nEl código original utiliza cancel_delayed_work() en xc5000_release(), lo que no garantiza que el elemento de trabajo retrasado timer_sleep haya completado totalmente si ya estaba en ejecución. Esto lleva a escenarios de uso después de liberación donde xc5000_release() puede liberar el xc5000_priv mientras timer_sleep todavía está activo e intenta desreferenciar el xc5000_priv.\n\nUna condición de carrera típica se ilustra a continuación:\n\nCPU 0 (hilo de liberación) | CPU 1 (callback de trabajo retrasado)\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\nReemplace cancel_delayed_work() con cancel_delayed_work_sync() para asegurar que el timer_sleep sea cancelado correctamente antes de que la memoria de xc5000_priv sea desasignada.\n\nSe consideró una preocupación por interbloqueo: xc5000_release() es llamado en un contexto de proceso y no está reteniendo ningún bloqueo que el elemento de trabajo timer_sleep también pudiera necesitar. Por lo tanto, el uso de la variante _sync() es seguro aquí.\n\nEste error fue inicialmente identificado mediante análisis estático.\n\n[hverkuil: corrige error tipográfico en Asunto: tunner -> tuner]"
}
],
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"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H",
"baseScore": 7.3,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "REQUIRED",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
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"ssvcData": {
"timestamp": "2026-10-15T21:55:59.194469Z",
"id": "CVE-2025-39994",
"options": [
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},
{
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{
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"role": "CISA Coordinator",
"version": "2.0.3"
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