{"cve":"CVE-2026-97975","nvd":{"published":"2026-09-25T11:17:25.427","modified":"2026-10-21T13:21:18.100","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sysfs: Fix NULL pointer dereference in device_del()\n\nA NULL pointer dereference in klist_put() occurs when a child device (such\nas a BNEP network device in bnep_session) is concurrently being\nunregistered while hci_conn_del_sysfs() reparents child devices.\n\nThis is caused by a race condition between hci_conn_del_sysfs() and\nconcurrent child device unregistration (e.g. bnep_session calling\nunregister_netdev()). During device unregistration, device_del() snapshots\na non-NULL parent pointer. Concurrently, hci_conn_del_sysfs() finds the\nchild device using device_find_any_child() and calls device_move() to\nreparent it to NULL, which removes the node from its parent's klist and\nclears knode_parent. Subsequently, device_del() calls\nklist_del(&dev->p->knode_parent) using the stale parent snapshot, causing\nklist_put() to dereference knode_klist(n)->put on an already removed node,\nresulting in a NULL pointer dereference.\n\nThis race was introduced by commit 27aabf27fd01 (\"Bluetooth: fix\nuse-after-free in device_for_each_child()\"), which replaced\ndevice_find_child(..., __match_tty) with device_find_any_child() in\nhci_conn_del_sysfs(). That change was intended to avoid a use-after-free\nwhere conn->dev outlived its parent hdev->dev when child devices held\nreferences to conn->dev, because conn->dev only held a reference to\nhdev->dev while registered in sysfs.\n\nFix the issue properly by taking an explicit reference to the parent device\nwith get_device(&hdev->dev) in hci_conn_init_sysfs() and dropping it with\nput_device(parent) in bt_link_release() when the conn device is freed. This\nensures that hdev->dev remains valid for the entire lifecycle of conn->dev,\nresolving the underlying use-after-free. With the parent reference held\nproperly, restore the __match_tty filter in hci_conn_del_sysfs() so that\ndevice_move() is only invoked on persistent RFCOMM TTY devices as\noriginally intended, eliminating the race condition with unregistering\nnetwork devices.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/55b76500546e5f2e7fdd7ae7283530b620de6e61","https://git.kernel.org/stable/c/66cc55b69928b742d24b4c5b66d195ae96900e48","https://git.kernel.org/stable/c/9b851b09b392da68bd715601f10a5adb2d8d19b8","https://git.kernel.org/stable/c/9e9ece97b8e716890793de261574b8efef7d8702","https://git.kernel.org/stable/c/eeabdb25c3209569367e99a85ca9a503b64a646d"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-97975","score":0.00168,"percentile":0.06109,"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."]}