{"id":"CVE-2026-97975","title":"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 …","summary":"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 …","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 27aabf27fd014ae037cc179c61b0bee7cff55b3d < eeabdb25c3209569367e99a85ca9a503b64a646d","Linux >= 27aabf27fd014ae037cc179c61b0bee7cff55b3d < 9e9ece97b8e716890793de261574b8efef7d8702","Linux >= 27aabf27fd014ae037cc179c61b0bee7cff55b3d < 9b851b09b392da68bd715601f10a5adb2d8d19b8","Linux 6894717a1ea363c5a27010ba604f957c309d282d","Linux fb91ce37dc9a37ea23cf32b6d7b667004e93d4c5","Linux a9584c897d1cba6265c78010bbb45ca5722c88bc","Linux 0f67ca2a80acf8b207240405b7f72d660665d3df","Linux de5a44f351ca7efd9add9851b218f5353e2224b7","Linux 91e2a2e4d1336333804cd31162984f01ad8cc70f","Linux 7b277bd569bb6a2777f0014f84b4344f444fd49d","Linux >= 5.4.297 < 5.5","Linux >= 5.10.231 < 5.11","Linux >= 5.15.174 < 5.16","Linux >= 6.1.120 < 6.2","Linux >= 6.6.64 < 6.7","Linux >= 6.11.11 < 6.12","Linux >= 6.12.2 < 6.13","Linux 6.13"],"published":"2026-09-25","updated":"2026-09-25","sourceUpdated":"2026-09-25T11:17:25.427","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-97975","references":[{"url":"https://git.kernel.org/stable/c/9b851b09b392da68bd715601f10a5adb2d8d19b8","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9e9ece97b8e716890793de261574b8efef7d8702","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/eeabdb25c3209569367e99a85ca9a503b64a646d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-25T11:06:38.870Z","slug":"CVE-2026-97975","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}