CVE-2025-39713 — media: rainshadow-cec: fix TOCTOU race condition in rain_interrupt()
In the Linux kernel, the following vulnerability has been resolved: media: rainshadow-cec: fix TOCTOU race condition in rain_interrupt() In the interrupt handler rain_interrupt(), the buffer full check on rain->buf_len is performed before acquiring rain->buf_lock. This creates a Time-of-Check to Time-of-Use (TOCTOU) race condition, as rain->buf_len is concurrently accessed and modified in the work handler rain_irq_work_handler() under the same lock. Multiple interrupt invocations can race, with each reading buf_len before it becomes full and then proceeding. This can lead to both interrupts attempting to write to the buffer, incrementing buf_len beyond its capacity (DATA_SIZE) and causing a buffer overflow. Fix this bug by moving the spin_lock() to before the buffer full check. This ensures that the check and the subsequent buffer modification are performed atomically, preventing the race condition. An corresponding spin_unlock() is added to the overflow path to correctly release the lock. This possible bug was found by an experimental static analysis tool developed by our team.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.1% (30-day exploitation probability)+0
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Debian Debian Linux, Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (logic error), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Debian | Debian Linux | version 11.0 | Vulnerable | NIST National Vulnerability Database |
| Linux | Linux |
≥ 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac and < 2964dbe631fd21ad7873b1752b895548d3c12496version 4.12≥ 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac and < 7af160aea26c7dc9e6734d19306128cce156ec40≥ 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac and < ff9dd3db6cd4c6b54a2ecbc58151bea4ec63bc59≥ 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac and < ed905fe7cba03cf22ae0b84cf1b73cd1c070423a≥ 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac and < 1c2769dc80255824542ea5a4ff1a07dcdeb1603f≥ 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac and < 3c3e33b7edca7a2d6a96801f287f9faeb684d655≥ 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac and < fbc81e78d75bf28972bc22b1599559557b1a1b83 and 1 more≥ 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac and < 6aaef1a75985865d8c6c5b65fb54152060faba48 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel | ≥ 6.13 and < 6.16.4≥ 6.7 and < 6.12.44≥ 6.2 and < 6.6.103≥ 5.16 and < 6.1.149≥ 5.11 and < 5.15.190≥ 5.5 and < 5.10.241≥ 4.12 and < 5.4.297 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 4.7 | CVSS 3.1 | Medium | 1.0 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
| 4.7 | CVSS 3.1 | Medium | — | — | GitHub, Inc. via GitHub Security Advisories |
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Fix documented
- Affected products added · linux/linux kernel, debian/debian linux
- CVSS changed · 4.7
- Source status changed · → Modified
- Record created in this database
- 2025
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 19, 2026 – Oct 19, 2026
- 1× Official description updated · Oct 19, 2026 – Oct 19, 2026
References
13 on the record
- git.kernel.org/stable/c/3c3e33b7edca7a2d6a96801f287f9faeb684d655
- git.kernel.org/stable/c/6aaef1a75985865d8c6c5b65fb54152060faba48
- git.kernel.org/stable/c/1c2769dc80255824542ea5a4ff1a07dcdeb1603f
- git.kernel.org/stable/c/7af160aea26c7dc9e6734d19306128cce156ec40
- git.kernel.org/stable/c/2964dbe631fd21ad7873b1752b895548d3c12496
- git.kernel.org/stable/c/ff9dd3db6cd4c6b54a2ecbc58151bea4ec63bc59
- git.kernel.org/stable/c/fbc81e78d75bf28972bc22b1599559557b1a1b83
- git.kernel.org/stable/c/ed905fe7cba03cf22ae0b84cf1b73cd1c070423a
- cert-portal.siemens.com/productcert/html/ssa-032379.html
- lists.debian.org/debian-lts-announce/2025/10/msg00007.html
- nvd.nist.gov/vuln/detail/CVE-2025-39713
- lists.debian.org/debian-lts-announce/2025/10/msg00008.html
- github.com/advisories/GHSA-pf4v-7q2j-5rw9
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-98868 dm-pcache: reject a kset that overruns its segment 1d
- Unknown CVE-2026-98866 sched/cache: Introduce task_struct->sched_cache_grp to fix UAF 1d
- Unknown CVE-2026-98867 dm-pcache: bound the logical key offset from persistent memory 1d
- Unknown CVE-2026-98865 sched_ext: Don't run ops.dequeue() with a DSQ lock held 1d
- Unknown CVE-2026-98864 sched_ext: Wait for SCX_OPSS_DISPATCHING before reenqueueing a task 1d
- Unknown CVE-2026-98863 KVM: x86: Re-pend GET_NESTED_STATE_PAGES if getting said pages fails 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2025-39713 is "media: rainshadow-cec: fix TOCTOU race condition in rain_interrupt()", rated Medium. It affects Debian Linux (Debian); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 4.7 describes technical severity. EPSS 0.14% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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