CVE-2024-26801 is a vulnerability identified in the Linux kernel's Bluetooth subsystem, specifically within the handling of the HCI_EV_HARDWARE_ERROR event. The flaw arises when the underlying Bluetooth (BT) controller becomes unresponsive, triggering a GPIO reset mechanism that prematurely frees the hci_dev structure. This leads to a use-after-free condition in the hci_error_reset function. The use-after-free vulnerability occurs because the reference count on the hci_dev device is not properly maintained during error handling, allowing the kernel to access memory that has already been freed. The vulnerability was observed on ChromeOS devices equipped with Intel AX201 Bluetooth controllers, as evidenced by the provided kernel call trace. The patch for this vulnerability involves holding the reference count on the hci_dev device while processing the hardware error event, preventing the premature freeing of the device structure and thus avoiding potential kernel crashes or memory corruption. This vulnerability is significant because it affects the Linux kernel's Bluetooth stack, which is widely used across many Linux distributions and embedded devices. Exploitation could lead to kernel crashes (denial of service) or potentially arbitrary code execution if an attacker can manipulate the use-after-free condition. However, exploitation would require triggering a hardware error event on the Bluetooth controller, which may limit the attack vector to local or proximate attackers with Bluetooth access. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet.

For European organizations, the impact of CVE-2024-26801 can vary depending on their reliance on Linux systems with Bluetooth capabilities. Enterprises using Linux-based devices, including servers, desktops, and embedded systems with Bluetooth hardware (such as Intel AX201), could face risks of system instability or denial of service due to kernel crashes triggered by this vulnerability. In environments where Bluetooth is used for critical operations or device management, such as manufacturing, healthcare, or transportation sectors, this vulnerability could disrupt operations. Additionally, if exploited, it could potentially allow attackers to escalate privileges or execute arbitrary code at the kernel level, compromising confidentiality and integrity of sensitive data. Given the widespread use of Linux in European public sector, research institutions, and technology companies, the vulnerability poses a moderate risk. However, the requirement for triggering a hardware error event and the absence of known exploits reduce the immediate threat level. Organizations with ChromeOS devices or other Linux-based platforms using Intel AX201 Bluetooth controllers should be particularly vigilant. The vulnerability also highlights the importance of maintaining up-to-date kernel versions to mitigate emerging threats.

1. Apply the official Linux kernel patch that addresses CVE-2024-26801 as soon as it becomes available in your distribution's updates. Monitor vendor advisories for updated kernel packages. 2. For organizations using ChromeOS or devices with Intel AX201 Bluetooth controllers, ensure firmware and kernel updates are applied promptly. 3. Limit Bluetooth exposure by disabling Bluetooth interfaces on systems where it is not required, especially on critical infrastructure or servers. 4. Implement network segmentation and access controls to restrict Bluetooth connectivity to trusted devices only. 5. Monitor system logs and kernel messages for unusual Bluetooth hardware error events or kernel crashes that could indicate attempted exploitation. 6. Employ endpoint detection and response (EDR) tools capable of detecting anomalous kernel behavior or memory corruption attempts. 7. For high-security environments, consider temporarily disabling Bluetooth functionality until patches are applied. 8. Educate system administrators about the risks associated with Bluetooth vulnerabilities and the importance of timely patch management.