{"id":"CVE-2025-38632","summary":"pinmux: fix race causing mux_owner NULL with active mux_usecount","details":"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-\u003epinmux 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-\u003emux_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-\u003emux_usecount--; //becomes 0\n                                         ..\n                                         mutex_unlock()\n\n  mutex_lock(desc-\u003emux)\n  desc-\u003emux_usecount++; // becomes 1\n  desc-\u003emux_owner = owner;\n  mutex_unlock(desc-\u003emux)\n\n                                         mutex_lock(desc-\u003emux)\n                                         desc-\u003emux_owner = NULL;\n                                         mutex_unlock(desc-\u003emux)\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.","modified":"2026-04-02T12:48:03.464525Z","published":"2025-08-22T16:00:40.423Z","related":["MGASA-2025-0234","MGASA-2025-0235","SUSE-SU-2025:03272-1","SUSE-SU-2025:03290-1","SUSE-SU-2025:03301-1","SUSE-SU-2025:03382-1","SUSE-SU-2025:03602-1","SUSE-SU-2025:03614-1","SUSE-SU-2025:03633-1","SUSE-SU-2025:03634-1","SUSE-SU-2025:20653-1","SUSE-SU-2025:20669-1","SUSE-SU-2025:20739-1","SUSE-SU-2025:20756-1","SUSE-SU-2025:21074-1","SUSE-SU-2025:21139-1","SUSE-SU-2025:21179-1","openSUSE-SU-2025:20081-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/38xxx/CVE-2025-38632.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0b075c011032f88d1cfde3b45d6dcf08b44140eb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/22b585cbd67d14df3b91529d1b990661c300faa9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9b2a3e7189028aa7c4d53a84364f2ea9fb209787"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9ea3f6b9a67be3476e331ce51cac316c2614a564"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b7bd6e3971eb7f0e34d2fdce1b18b08094e0c804"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/38xxx/CVE-2025-38632.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38632"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"2da32aed4a97ca1d70fb8b77926f72f30ce5fb4b"},{"fixed":"9b2a3e7189028aa7c4d53a84364f2ea9fb209787"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"c11e2ec9a780f54982a187ee10ffd1b810715c85"},{"fixed":"9ea3f6b9a67be3476e331ce51cac316c2614a564"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5a3e85c3c397c781393ea5fb2f45b1f60f8a4e6e"},{"fixed":"b7bd6e3971eb7f0e34d2fdce1b18b08094e0c804"},{"fixed":"22b585cbd67d14df3b91529d1b990661c300faa9"},{"fixed":"0b075c011032f88d1cfde3b45d6dcf08b44140eb"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-38632.json"}}],"schema_version":"1.7.5"}