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Fencer Intel
high 7.3

CVE-2025-39994 json

media: tuner: xc5000: Fix use-after-free in xc5000_release

published last yr. modified 21d ago also EUVD-2025-34579

cvss
7.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits
0
none known

Summary

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]

Patch / fix

  • Linux Linux 5.4.301, 5.10.246, 5.15.195, 6.1.156, 6.6.111, 6.12.51, 6.16.11, 6.17.1, 6.18
  • linux Debian 12 6.1.158-1
  • linux Debian 13 6.12.57-1
  • linux Debian 14 6.16.11-1

debian advisories DEBIAN-CVE-2025-39994

  • linux Ubuntu 22.04 LTS 5.15.0-170.180
  • linux Ubuntu 24.04 LTS 6.8.0-106.106
  • linux Ubuntu 25.10 6.17.0-6.6
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1100.107
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1050.53
  • linux-aws Ubuntu 25.10 6.17.0-1003.3
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1100.109
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1052.55

ubuntu advisories UBUNTU-CVE-2025-39994

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 8 4.18.0-553.171.1.el8_10
  • perf RHEL 8 4.18.0-553.171.1.el8_10
  • bpftool RHEL 8 4.18.0-553.171.1.el8_10
  • kernel-core RHEL 8 4.18.0-553.171.1.el8_10
  • kernel-tools RHEL 8 4.18.0-553.171.1.el8_10
  • python3-perf RHEL 8 4.18.0-553.171.1.el8_10
  • kernel-modules RHEL 8 4.18.0-553.171.1.el8_10
  • kernel-zfcpdump RHEL 8 4.18.0-553.171.1.el8_10

red hat advisories RHSA-2026:75747RHSA-2026:75746

  • kernel-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
  • kernel-syms-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
  • kernel-rt_debug Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
  • kernel-source-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
  • kernel-rt Linux Micro 6.2 6.12.0-160000.7.1
  • kernel-64kb SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.7.1
  • kernel-source SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.7.1
  • kernel-default SLES 16.0, SLE High Availability Extension 16.0, Linux Micro 6.2 +1 more 6.12.0-160000.7.1

suse advisories SUSE-SU-2025:4301-1SUSE-SU-2025:21080-1SUSE-SU-2025:21147-1SUSE-SU-2025:21180-1SUSE-SU-2026:20561-1SUSE-SU-2025:21052-1

  • kernel-source-longterm openSUSE Tumbleweed 6.18.16-1.1
  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.7.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.7.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.7.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.7.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.7.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.7.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.7.1

opensuse advisories openSUSE-SU-2026:10301-1openSUSE-SU-2025:20091-1openSUSE-SU-2025:15671-1

  • kernel-rt AlmaLinux 8 4.18.0-553.171.1.rt7.512.el8_10
  • kernel-rt-core AlmaLinux 8 4.18.0-553.171.1.rt7.512.el8_10
  • kernel-rt-modules AlmaLinux 8 4.18.0-553.171.1.rt7.512.el8_10
  • kernel-rt-debug-core AlmaLinux 8 4.18.0-553.171.1.rt7.512.el8_10
  • kernel-rt-debug-modules AlmaLinux 8 4.18.0-553.171.1.rt7.512.el8_10
  • kernel-rt-modules-extra AlmaLinux 8 4.18.0-553.171.1.rt7.512.el8_10
  • kernel-rt-debug-modules-extra AlmaLinux 8 4.18.0-553.171.1.rt7.512.el8_10
  • kernel AlmaLinux 8 4.18.0-553.171.1.el8_10

almalinux advisories ALSA-2026:75746ALSA-2026:75747

  • kernel-rt Rocky Linux 8 4.18.0-553.171.1.rt7.512.el8_10
  • kernel Rocky Linux 8 4.18.0-553.171.1.el8_10

rocky linux advisories RLSA-2026:75746RLSA-2026:75747

  • kernel Azure Linux 3.0 6.6.112.1-1

azure linux advisories AZL-68510

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-39994 updated cvss 5.8

kernel: Linux kernel: Use-after-free in xc5000 tuner driver due to race condition

  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.171.1.el8_10, kernel 4.18.0-553.171.1.el8_10, bpftool 4.18.0-553.171.1.el8_10, kernel-core 4.18.0-553.171.1.el8_10, kernel-tools 4.18.0-553.171.1.el8_10, python3-perf 4.18.0-553.171.1.el8_10, +15 more Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.171.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.171.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.171.1.el8_10
    fixed: vendor fix RHSA-2026:75747
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.171.1.rt7.512.el8_10, kernel-rt-kvm 4.18.0-553.171.1.rt7.512.el8_10, kernel-rt-core 4.18.0-553.171.1.rt7.512.el8_10, kernel-rt-modules 4.18.0-553.171.1.rt7.512.el8_10, kernel-rt-debug-kvm 4.18.0-553.171.1.rt7.512.el8_10, kernel-rt-debug-core 4.18.0-553.171.1.rt7.512.el8_10, +4 more Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.171.1.rt7.512.el8_10, kernel-rt-core 4.18.0-553.171.1.rt7.512.el8_10, kernel-rt-modules 4.18.0-553.171.1.rt7.512.el8_10, kernel-rt-debug-core 4.18.0-553.171.1.rt7.512.el8_10, kernel-rt-debug-modules 4.18.0-553.171.1.rt7.512.el8_10, kernel-rt-modules-extra 4.18.0-553.171.1.rt7.512.el8_10, +2 more
    fixed: vendor fix RHSA-2026:75746
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
25d ago

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 7.3 CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

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