Description
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.
Published: 2026-06-25
Score: n/a
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

A failure in the Bluetooth HCI UART initialization path in the Linux kernel can cause the SRCU structure allocated by hci_alloc_dev() not to be cleaned up when bt_host_release() is invoked before hci_register_dev() succeeds. The missing cleanup leaves per‑CPU memory allocated, which steadily accumulates as the device is repeatedly attempted to be provisioned and fails. This improper release of resources (CWE‑687) can result in kernel memory exhaustion, ultimately bringing the system to a denial‑of‑service state.

Affected Systems

All Linux kernel builds that include the Bluetooth subsystem prior to the fix commit are affected. The vulnerability exists in every distribution that ships the unsupported kernel version; any vendor using a kernel older than the applied patch is at risk.

Risk and Exploitability

The CVSS score is not publicly listed, and EPSS is not available, but the lack of this vulnerability in the CISA KEV catalog and the absence of a known remote exploitation path suggests a moderate risk. An attacker would need to force repeated HCI device initialization failures, which typically requires local or privileged access; the attack vector is therefore inferred to be local or privileged rather than remote. The primary impact is availability‑downtime due to memory exhaustion rather than confidentiality or integrity compromise.

Generated by OpenCVE AI on June 25, 2026 at 12:06 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Update to a kernel version that includes the cleanup_srcu_struct() fix for hci_alloc_dev()
  • Reboot the system after upgrading to ensure the new code path is active
  • Verify per‑CPU memory usage and the number of active Bluetooth HCI devices to confirm the leak has been resolved

Generated by OpenCVE AI on June 25, 2026 at 12:06 UTC.

Tracking

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Advisories

No advisories yet.

History

Thu, 25 Jun 2026 12:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-687

Thu, 25 Jun 2026 09:15:00 +0000

Type Values Removed Values Added
Description 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.
Title Bluetooth: fix memory leak in error path of hci_alloc_dev()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-06-25T08:39:43.951Z

Reserved: 2026-06-09T07:44:35.394Z

Link: CVE-2026-53252

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-25T12:15:03Z

Weaknesses
  • CWE-687

    Function Call With Incorrectly Specified Argument Value