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]
Metrics
Affected Vendors & Products
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References
History
Wed, 15 Oct 2025 10:45:00 +0000
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Wed, 15 Oct 2025 08:15:00 +0000
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| 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] | |
| Title | media: tuner: xc5000: Fix use-after-free in xc5000_release | |
| References |
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-10-15T10:22:24.152Z
Reserved: 2025-04-16T07:20:57.150Z
Link: CVE-2025-39994
Vulnrichment
No data.
NVD
Status : Received
Published: 2025-10-15T08:15:37.567
Modified: 2025-10-15T11:15:36.790
Link: CVE-2025-39994
Redhat
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OpenCVE Enrichment
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