VulnerabilityPublished 22 Aug 2025Updated 30 Oct 2026

CVE-2025-38632: Linux kernel · pinmux: fix race causing mux_owner NULL with active mux_usecount

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in b7bd6e3971eb7f0e34d2fdce1b18b08094e0c804 : update Linux kernel when convenient.

Data as of 30 Oct 2026, 12:33 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Patch: Available – fixed in b7bd6e3971eb7f0e34d2fdce1b18b08094e0c804, 8434dec94e73cad527341d6280895191d949a702, 22b585cbd67d14df3b91529d1b990661c300faa9 +5

Exploitation evidence

Disclosed: evidence found.
CVE published 22 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected >=6.6.66 <6.6.102 >=6.12.5 <6.12.42	Fixed in b7bd6e3971eb7f0e34d2fdce1b18b08094e0c804 8434dec94e73cad527341d6280895191d949a702 22b585cbd67d14df3b91529d1b990661c300faa9 9ea3f6b9a67be3476e331ce51cac316c2614a564 9b2a3e7189028aa7c4d53a84364f2ea9fb209787 6.12.42 6.6.102 0b075c011032f88d1cfde3b45d6dcf08b44140eb
LinuxLinux	Affected =6.13	Fixed in–

Description

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.

References

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