{"cve":"CVE-2025-38632","nvd":{"published":"2025-08-22T16:15:37.033","modified":"2026-10-30T13:18:06.903","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\npinmux: fix race causing mux_owner NULL with active mux_usecount\n\ncommit 5a3e85c3c397 (\"pinmux: Use sequential access to access\ndesc->pinmux data\") tried to address the issue when two client of the\nsame gpio calls pinctrl_select_state() for the same functionality, was\nresulting in NULL pointer issue while accessing desc->mux_owner.\nHowever, issue was not completely fixed due to the way it was handled\nand it can still result in the same NULL pointer.\n\nThe issue occurs due to the following interleaving:\n\n     cpu0 (process A)                   cpu1 (process B)\n\n      pin_request() {                   pin_free() {\n\n                                         mutex_lock()\n                                         desc->mux_usecount--; //becomes 0\n                                         ..\n                                         mutex_unlock()\n\n  mutex_lock(desc->mux)\n  desc->mux_usecount++; // becomes 1\n  desc->mux_owner = owner;\n  mutex_unlock(desc->mux)\n\n                                         mutex_lock(desc->mux)\n                                         desc->mux_owner = NULL;\n                                         mutex_unlock(desc->mux)\n\nThis sequence leads to a state where the pin appears to be in use\n(`mux_usecount == 1`) but has no owner (`mux_owner == NULL`), which can\ncause NULL pointer on next pin_request on the same pin.\n\nEnsure that updates to mux_usecount and mux_owner are performed\natomically under the same lock. Only clear mux_owner when mux_usecount\nreaches zero and no new owner has been assigned.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","score":4.7},"cwes":["CWE-362","CWE-476"],"references":["https://git.kernel.org/stable/c/0b075c011032f88d1cfde3b45d6dcf08b44140eb","https://git.kernel.org/stable/c/22b585cbd67d14df3b91529d1b990661c300faa9","https://git.kernel.org/stable/c/8434dec94e73cad527341d6280895191d949a702","https://git.kernel.org/stable/c/9b2a3e7189028aa7c4d53a84364f2ea9fb209787","https://git.kernel.org/stable/c/9ea3f6b9a67be3476e331ce51cac316c2614a564"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-30T13:47:47.119061695+00:00"},"epss":{"cve":"CVE-2025-38632","score":0.00119,"percentile":0.01765,"date":"2026-10-30"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}