CVE-2026-74302: Bluetooth: hci_core: Fix UAF in hci_unregister_dev()

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-15 · updated 2026-10-30

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_core: Fix UAF in hci_unregister_dev() hci_unregister_dev() does not disable cmd_timer and ncmd_timer before the hci_dev structure is freed. If a timeout fires during device teardown, the callback dereferences freed memory (including the hdev->reset function pointer), leading to a use-after-free. Add disable_delayed_work_sync() calls alongside the existing disable_work_sync() calls to ensure both timers are fully quiesced before teardown proceeds.

Affected products

Linux: from 6.1.101 before 6.1.191; from 6.6.42 before 6.6.160; from 4.19.319 before 4.20; from 5.4.281 before 5.5; from 5.10.223 before 5.11; from 5.15.164 before 5.16 — fixed in 6.1.191, 6.6.160, 4.20, 5.5, 5.11, 5.16

How to fix

Upgrade to a fixed version: Linux 6.1.191, 6.6.160, 4.20, 5.5. Check the vendor advisory for mitigations.

References

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