Bug 2492818 (CVE-2026-53252)

Summary: CVE-2026-53252 kernel: Bluetooth: fix memory leak in error path of hci_alloc_dev()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's Bluetooth subsystem. Specifically, an issue in the error handling path of the `hci_alloc_dev()` function within the Bluetooth Host Controller Interface (HCI) Universal Asynchronous Receiver/Transmitter (UART) configuration can lead to a memory leak. This occurs when device initialization fails before proper registration, preventing the necessary cleanup of allocated memory. The continuous leakage of memory could potentially impact system stability and resource availability.
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Description OSIDB Bzimport 2026-06-25 10:07:23 UTC 
In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: fix memory leak in error path of hci_alloc_dev()

Early failures in Bluetooth HCI UART configuration leak SRCU percpu
memory.

When device initialization fails before hci_register_dev() completes,
the HCI_UNREGISTER flag is never set. As a result, when the device
reference count reaches zero, bt_host_release() evaluates this flag as
false and falls back to a direct kfree(hdev).

Because hci_release_dev() is bypassed, the SRCU struct initialized
early in hci_alloc_dev() is never cleaned up, resulting in a leak of
percpu memory.

Fix the leak by explicitly calling cleanup_srcu_struct() in the
fallback (unregistered) branch of bt_host_release() before freeing
the device.
Comment 1 Keith Grant 2026-06-26 01:15:01 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062514-CVE-2026-53252-4306@gregkh/T