Privilege escalation via post-unregister HCI queue use-after-free
Published Feb 26, 2025 · Updated Aug 5, 2026
Use-after-free in Linux kernel 5.17 Bluetooth HCI synchronization allows local users to execute code in kernel context. hci_cmd_sync_queue accepts work after HCI_UNREGISTER is set, leaving queued timeout work to access an hci_dev freed by hci_unregister_dev. Exploitation requires low-privileged local access to create and tear down a virtual HCI controller while racing a concurrent queue operation, and failed exploitation can panic the kernel.
Summary
What happened
Use-after-free in Linux kernel 5.17 Bluetooth HCI synchronization allows local users to execute code in kernel context. hci_cmd_sync_queue accepts work after HCI_UNREGISTER is set, leaving queued timeout work to access an hci_dev freed by hci_unregister_dev. Exploitation requires low-privileged local access to create and tear down a virtual HCI controller while racing a concurrent queue operation, and failed exploitation can panic the kernel.
The record
- CVE
- CVE-2022-49136
- Published
- Feb 26, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-416, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 26, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=5.17
- Affected versionversion=6a98e3836fa2077b169f10a35c2ca9952d53f987 <0b94f2651f56b9e4aa5f012b0d7eb57308c773cf
- Affected versionversion=6a98e3836fa2077b169f10a35c2ca9952d53f987 <1c69ef84a808676cceb69210addf5df45b741323
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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