CVE-2025-38632 — pinmux: fix race causing mux_owner NULL with active mux_usecount
In the Linux kernel, the following vulnerability has been resolved: pinmux: fix race causing mux_owner NULL with active mux_usecount commit 5a3e85c3c397 ("pinmux: Use sequential access to access desc->pinmux data") tried to address the issue when two client of the same gpio calls pinctrl_select_state() for the same functionality, was resulting in NULL pointer issue while accessing desc->mux_owner. However, issue was not completely fixed due to the way it was handled and it can still result in the same NULL pointer. The issue occurs due to the following interleaving: cpu0 (process A) cpu1 (process B) pin_request() { pin_free() { mutex_lock() desc->mux_usecount--; //becomes 0 .. mutex_unlock() mutex_lock(desc->mux) desc->mux_usecount++; // becomes 1 desc->mux_owner = owner; mutex_unlock(desc->mux) mutex_lock(desc->mux) desc->mux_owner = NULL; mutex_unlock(desc->mux) This sequence leads to a state where the pin appears to be in use (`mux_usecount == 1`) but has no owner (`mux_owner == NULL`), which can cause NULL pointer on next pin_request on the same pin. Ensure that updates to mux_usecount and mux_owner are performed atomically under the same lock. Only clear mux_owner when mux_usecount reaches zero and no new owner has been assigned.
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)
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 (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 |
|---|---|---|---|---|
| Linux | Linux |
≥ d25e45dcf8e32062f7935e4ba154869043812ab6 and < 8434dec94e73cad527341d6280895191d949a702≥ 2da32aed4a97ca1d70fb8b77926f72f30ce5fb4b and < 9b2a3e7189028aa7c4d53a84364f2ea9fb209787≥ c11e2ec9a780f54982a187ee10ffd1b810715c85 and < 9ea3f6b9a67be3476e331ce51cac316c2614a564≥ 5a3e85c3c397c781393ea5fb2f45b1f60f8a4e6e and < b7bd6e3971eb7f0e34d2fdce1b18b08094e0c804≥ 5a3e85c3c397c781393ea5fb2f45b1f60f8a4e6e and < 22b585cbd67d14df3b91529d1b990661c300faa9≥ 5a3e85c3c397c781393ea5fb2f45b1f60f8a4e6e and < 0b075c011032f88d1cfde3b45d6dcf08b44140eb≥ 6.6.66 and < 6.6.102≥ 6.12.5 and < 6.12.42 and 1 moreversion 6.13 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel | ≥ 6.6.66 and < 6.6.102≥ 6.12.5 and < 6.12.42≥ 6.13 and < 6.15.10≥ 6.16 and < 6.16.1 | 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.
EPSS over time FIRST
Oct 29, 2026 → Oct 30, 2026 · 2 reading(s) · max 0.12%
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
- 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 30, 2026 – Oct 30, 2026
- 1× Official description updated · Oct 30, 2026 – Oct 30, 2026
References
8 on the record
- git.kernel.org/stable/c/9ea3f6b9a67be3476e331ce51cac316c2614a564
- git.kernel.org/stable/c/0b075c011032f88d1cfde3b45d6dcf08b44140eb
- git.kernel.org/stable/c/b7bd6e3971eb7f0e34d2fdce1b18b08094e0c804
- git.kernel.org/stable/c/22b585cbd67d14df3b91529d1b990661c300faa9
- git.kernel.org/stable/c/9b2a3e7189028aa7c4d53a84364f2ea9fb209787
- git.kernel.org/stable/c/8434dec94e73cad527341d6280895191d949a702
- github.com/advisories/GHSA-rpg5-5rc2-v629
- nvd.nist.gov/vuln/detail/CVE-2025-38632
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 3d
- Unknown CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 3d
- Unknown CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 3d
- Unknown CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 3d
- Unknown CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 3d
- Unknown CVE-2026-99210 accel/rocket: clear rdev on device init failure 3d
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-2025-38632 is "pinmux: fix race causing mux_owner NULL with active mux_usecount", rated Medium. It affects Linux (Linux); 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 0.12% 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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