{"id":"CVE-2025-38632","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-38632","generatedAt":"2026-10-28T03:28:24.414Z","title":"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…","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.","published":"2025-08-22T16:15:37.000Z","lastModified":"2026-06-17T09:17:15.000Z","status":"Analyzed","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":4.7,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-362","CWE-476"],"affected":["linux/linux kernel"],"epss":{"score":0.00119,"percentile":0.01768,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.12%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/0b075c011032f88d1cfde3b45d6dcf08b44140eb","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/22b585cbd67d14df3b91529d1b990661c300faa9","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9b2a3e7189028aa7c4d53a84364f2ea9fb209787","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9ea3f6b9a67be3476e331ce51cac316c2614a564","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b7bd6e3971eb7f0e34d2fdce1b18b08094e0c804","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-38632","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}