{"cve":"CVE-2025-68245","nvd":{"published":"2025-12-16T15:15:53.767","modified":"2026-10-14T13:10:00.187","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: netpoll: fix incorrect refcount handling causing incorrect cleanup\n\ncommit efa95b01da18 (\"netpoll: fix use after free\") incorrectly\nignored the refcount and prematurely set dev->npinfo to NULL during\nnetpoll cleanup, leading to improper behavior and memory leaks.\n\nScenario causing lack of proper cleanup:\n\n1) A netpoll is associated with a NIC (e.g., eth0) and netdev->npinfo is\n   allocated, and refcnt = 1\n   - Keep in mind that npinfo is shared among all netpoll instances. In\n     this case, there is just one.\n\n2) Another netpoll is also associated with the same NIC and\n   npinfo->refcnt += 1.\n   - Now dev->npinfo->refcnt = 2;\n   - There is just one npinfo associated to the netdev.\n\n3) When the first netpolls goes to clean up:\n   - The first cleanup succeeds and clears np->dev->npinfo, ignoring\n     refcnt.\n     - It basically calls `RCU_INIT_POINTER(np->dev->npinfo, NULL);`\n   - Set dev->npinfo = NULL, without proper cleanup\n   - No ->ndo_netpoll_cleanup() is either called\n\n4) Now the second target tries to clean up\n   - The second cleanup fails because np->dev->npinfo is already NULL.\n     * In this case, ops->ndo_netpoll_cleanup() was never called, and\n       the skb pool is not cleaned as well (for the second netpoll\n       instance)\n  - This leaks npinfo and skbpool skbs, which is clearly reported by\n    kmemleak.\n\nRevert commit efa95b01da18 (\"netpoll: fix use after free\") and adds\nclarifying comments emphasizing that npinfo cleanup should only happen\nonce the refcount reaches zero, ensuring stable and correct netpoll\nbehavior.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/49c8d2c1f94cc2f4d1a108530d7ba52614b874c2","https://git.kernel.org/stable/c/4afd4ebbad52aa146838ec23082ba393e426a2bb","https://git.kernel.org/stable/c/890472d6fbf062e6de7fdd56642cb305ab79d669","https://git.kernel.org/stable/c/8e6a50edad11e3e1426e4c29e7aa6201f3468ac2","https://git.kernel.org/stable/c/9a51b5ccd1c79afec1c03a4e1e6688da52597556"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:17:07.138532058+00:00"},"epss":{"cve":"CVE-2025-68245","score":0.00201,"percentile":0.09915,"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."]}