CVE-2026-97975
Vulnérabilité non évaluée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sysfs: Fix NULL pointer dereference in device_del() A NULL pointer dereference in klist_put() occurs when a child device (such as a BNEP network device in bnep_session) is concurrently being unregistered while hci_conn_del_sysfs() reparents child devices. This is caused by a race condition between hci_conn_del_sysfs() and concurrent child device unregistration (e.g. bnep_session calling unregister_netdev()). During device unregistration, device_del() snapshots a non-NULL parent pointer. Concurrently, hci_conn_del_sysfs() finds the child device using device_find_any_child() and calls device_move() to reparent it to NULL, which removes the node from its parent's klist and clears knode_parent. Subsequently, device_del() calls klist_del(&dev->p->knode_parent) using the stale parent snapshot, causing klist_put() to dereference knode_klist(n)->put on an already removed node, resulting in a NULL pointer dereference. This race was introduced by commit 27aabf27fd01 ("Bluetooth: fix use-after-free in device_for_each_child()"), which replaced device_find_child(..., __match_tty) with device_find_any_child() in hci_conn_del_sysfs(). That change was intended to avoid a use-after-free where conn->dev outlived its parent hdev->dev when child devices held references to conn->dev, because conn->dev only held a reference to hdev->dev while registered in sysfs. Fix the issue properly by taking an explicit reference to the parent device with get_device(&hdev->dev) in hci_conn_init_sysfs() and dropping it with put_device(parent) in bt_link_release() when the conn device is freed. This ensures that hdev->dev remains valid for the entire lifecycle of conn->dev, resolving the underlying use-after-free. With the parent reference held properly, restore the __match_tty filter in hci_conn_del_sysfs() so that device_move() is only invoked on persistent RFCOMM TTY devices as originally intended, eliminating the race condition with unregistering network devices.
Gravité et risque d'exploitation
CVE-2026-97975 obtient un score CVSS de 0.0/10, soit une gravité non évaluée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.17 %, ce qui la place devant 5.4 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions 6.13, <5.11, 91e2a2e4d1336333804cd31162984f01ad8cc70f, 7.2.7, 6.18.53, de5a44f351ca7efd9add9851b218f5353e2224b7, <6.13, 6.1.120, 0, <9e9ece97b8e716890793de261574b8efef7d8702, 5.10.231, <9b851b09b392da68bd715601f10a5adb2d8d19b8, 5.4.297, 5.15.174, 6.12.2, 6.6.64, <eeabdb25c3209569367e99a85ca9a503b64a646d, <6.12, 6894717a1ea363c5a27010ba604f957c309d282d, <5.5, <5.16, a9584c897d1cba6265c78010bbb45ca5722c88bc, 6.11.11, <=6.18.*, <6.2, fb91ce37dc9a37ea23cf32b6d7b667004e93d4c5, 0f67ca2a80acf8b207240405b7f72d660665d3df, <=7.2.*, <6.7, 27aabf27fd014ae037cc179c61b0bee7cff55b3d, <=*, 7b277bd569bb6a2777f0014f84b4344f444fd49d, 7.3) est présent sur votre parc.
- Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
- À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
- Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.