media: tuner: xc5000: Fix use-after-free in xc5000_release
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
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]
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 3.16 and later | 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 | Patch available | CNA |
- Linux VendorLinux Affected 3.16 and later Fixed in 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 Patch available CNA
Remediation
- Fix · CNA Linux (Linux) Fixed in 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
Red Hat 2 advisories
- RHSA-2026:75747 Released 2026-10-05 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.171.1.el8_10, kernel-4.18.0-553.171.1.el8_10, kernel-abi-stablelists-4.18.0-553.171.1.el8_10 +19
- Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.171.1.el8_10
- RHSA-2026:75746 Released 2026-10-05 · Red Hat rating Importantkernel-rt security, bug fix, and enhancement update
- Red Hat Enterprise Linux NFV (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-debug-4.18.0-553.171.1.rt7.512.el8_10 +9
- 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-debug-4.18.0-553.171.1.rt7.512.el8_10 +7
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2026:75747 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2026:75747 |
| Red Hat Enterprise Linux NFV (v. 8) | Fixed | RHSA-2026:75746 |
| Red Hat Enterprise Linux RT (v. 8) | Fixed | RHSA-2026:75746 |
Not affected: 4 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2025-39994
- 2026-10-03 Alias added: GHSA-ghgh-r6c5-cgx8
- 2026-10-05 Fix available: RHSA-2026:75746 · Red Hat
- 2026-10-05 Fix available: RHSA-2026:75747 · Red Hat
- 2026-10-05 Fix available: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8), Red Hat Enterprise Linux NFV (v. 8) +1 · Red Hat
- 2026-10-16 CISA SSVC decision points changed
References
Other 9
- https://git.kernel.org/stable/c/bc4ffd962ce16a154c44c68853b9d93f5b6fc4b8
- https://git.kernel.org/stable/c/e2f5eaafc0306a76fb1cb760aae804b065b8a341
- https://git.kernel.org/stable/c/3f876cd47ed8bca1e28d68435845949f51f90703
- https://git.kernel.org/stable/c/df0303b4839520b84d9367c2fad65b13650a4d42
- https://git.kernel.org/stable/c/71ed8b81a4906cb785966910f39cf7f5ad60a69e
- https://git.kernel.org/stable/c/effb1c19583bca7022fa641a70766de45c6d41ac
- https://git.kernel.org/stable/c/9a00de20ed8ba90888479749b87bc1532cded4ce
- https://git.kernel.org/stable/c/4266f012806fc18e46da4a04d130df59a4946f93
- https://git.kernel.org/stable/c/40b7a19f321e65789612ebaca966472055dab48c
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Sources
- CVE-2025-39994 · CVE Program
- CVE-2025-39994 · NVD
- FIRST EPSS
- GHSA-ghgh-r6c5-cgx8 · GitHub Advisory Database · CC BY 4.0
- CVE-2025-39994 · Red Hat security data · CC BY 4.0
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