CVE-2026-74509

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: Fix advertising data UAFs hci_find_adv_instance() returns an adv_info pointer that is valid only while hdev->lock is held. The advertising command-sync paths perform instance lookups without that lock and, in some cases, retain the pointer while waiting for a controller response. An advertising termination event can therefore interleave as follows: hci_cmd_sync_work hci_rx_work hci_find_adv_instance() __hci_cmd_sync_status() wait for controller reply hci_dev_lock() hci_remove_adv_instance() kfree(adv) adv->scan_rsp_changed = false KASAN reported: BUG: KASAN: slab-use-after-free in hci_set_ext_scan_rsp_data_sync+0x2e1/0x300 Write of size 1 at addr ffff88810a45d21d by task kworker/u17:0/88 Workqueue: hci0 hci_cmd_sync_work Call Trace: hci_set_ext_scan_rsp_data_sync+0x2e1/0x300 hci_schedule_adv_instance_sync+0x390/0x4c0 hci_cmd_sync_work+0x173/0x300 Allocated by task 87: hci_add_adv_instance+0x538/0xac0 add_advertising+0x885/0x1160 Freed by task 89: kfree+0x131/0x3c0 hci_remove_adv_instance+0x1d8/0x3b0 hci_le_ext_adv_term_evt+0x17b/0x730 Protect the instance lookup and payload construction in the extended advertising, scan response, and periodic advertising data paths. Snapshot the advertising parameters under hdev->lock, but release the lock before waiting for the controller. Clear advertising-data dirty bits before issuing their commands and restore them after a failure using a fresh lookup. Likewise, update the reported transmit power through a fresh lookup after the parameter command completes. No adv_info pointer then survives an HCI command wait.

Gravité et risque d'exploitation

CVE-2026-74509 obtient un score CVSS de 8.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.25 %, ce qui la place devant 15.2 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <=6.1.*, 7.2, <=6.12.*, 0, <=7.1.*, 6.6.154, 6.12.103, 42fe380baaaccbe635c34ca07b29d19b9ec2498d, <5.17, 5.15.210, <95cdcd8c82a501931fd3ae9b3811b0b6da167e94, <=6.6.*, <c4cec575a6d6f7c36808a3a0017b0675968bb06b, <b16ebdbebd2d37f4cdc590bc3e9db71fe90350a3, <5.16, <=6.18.*, 6.1.184, <cdc36db204ffd97b947d64374cf23a210dc74777, <565971488191bf54a87a417abafab6ad0de72201, <=*, 7.1.8, 6.18.44, <eb1d8318764de7216e6dbba29a24d69f7ce51348, 5.17, cba6b758711cab946c787f7c15be92cc749b8e1f) 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.

Références

• https://git.kernel.org/stable/c/565971488191bf54a87a417abafab6ad0de72201
• https://git.kernel.org/stable/c/c4cec575a6d6f7c36808a3a0017b0675968bb06b
• https://git.kernel.org/stable/c/95cdcd8c82a501931fd3ae9b3811b0b6da167e94
• https://git.kernel.org/stable/c/eb1d8318764de7216e6dbba29a24d69f7ce51348
• https://git.kernel.org/stable/c/b16ebdbebd2d37f4cdc590bc3e9db71fe90350a3
• https://git.kernel.org/stable/c/cdc36db204ffd97b947d64374cf23a210dc74777