Bug 2516911 (CVE-2026-74302)

Summary: CVE-2026-74302 kernel: Bluetooth: hci_core: Fix UAF in hci_unregister_dev()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Bluetooth subsystem of the Linux kernel. During the unregistration of a Bluetooth device, the system fails to properly disable timers before freeing the associated memory. This can lead to a use-after-free vulnerability, where the system attempts to access memory that has already been released. Exploiting this flaw could result in system instability, crashes, or potentially allow an attacker to execute arbitrary code.
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Description OSIDB Bzimport 2026-08-15 06:39:59 UTC 
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.
Comment 1 Keith Grant 2026-08-20 15:41:09 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081550-CVE-2026-74302-61a5@gregkh/T