{"cve":"CVE-2025-40231","nvd":{"published":"2025-12-04T16:16:15.870","modified":"2026-10-19T21:10:00.160","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvsock: fix lock inversion in vsock_assign_transport()\n\nSyzbot reported a potential lock inversion deadlock between\nvsock_register_mutex and sk_lock-AF_VSOCK when vsock_linger() is called.\n\nThe issue was introduced by commit 687aa0c5581b (\"vsock: Fix\ntransport_* TOCTOU\") which added vsock_register_mutex locking in\nvsock_assign_transport() around the transport->release() call, that can\ncall vsock_linger(). vsock_assign_transport() can be called with sk_lock\nheld. vsock_linger() calls sk_wait_event() that temporarily releases and\nre-acquires sk_lock. During this window, if another thread hold\nvsock_register_mutex while trying to acquire sk_lock, a circular\ndependency is created.\n\nFix this by releasing vsock_register_mutex before calling\ntransport->release() and vsock_deassign_transport(). This is safe\nbecause we don't need to hold vsock_register_mutex while releasing the\nold transport, and we ensure the new transport won't disappear by\nobtaining a module reference first via try_module_get().","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/09bba278ccde25a14b6e5088a9e65a8717d0cccf","https://git.kernel.org/stable/c/251caee792a21eb0b781aab91362b422c945e162","https://git.kernel.org/stable/c/42ed0784d11adebf748711e503af0eb9f1e6d81d","https://git.kernel.org/stable/c/a2a4346eea8b4cb75037dbcb20b98cb454324f80","https://git.kernel.org/stable/c/b44182c116778feaa05da52a426aeb9da1878dcf"],"products":[],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2025-40231","score":0.00207,"percentile":0.10662,"date":"2026-10-25"},"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."]}