CVE-2023-52457 is a vulnerability identified in the Linux kernel's serial driver subsystem, specifically affecting the 8250 UART driver implementation on OMAP platforms. The issue arises during the device removal process in the driver core. When the function pm_runtime_resume_and_get() fails, the driver's .remove() callback returns an error code. However, the driver core ignores this error and proceeds to remove the device regardless, emitting only a minimal error message. This behavior leads to a resource leak because the cleanup function serial8250_unregister_port() is skipped. Consequently, some UART resources remain allocated, which can cause a use-after-free condition if those resources are accessed later. The vulnerability is rooted in improper error handling and cleanup logic in the driver removal sequence, which can leave kernel memory in an inconsistent state. The patch replaces the error return with a more informative error message and ensures that cleanup proceeds correctly, preventing resource leaks and potential use-after-free scenarios. The affected Linux kernel versions include multiple commits identified by their hashes, indicating that this issue is present in recent kernel versions prior to the patch. No known exploits are reported in the wild as of the publication date (February 23, 2024).

For European organizations, this vulnerability poses a risk primarily to systems running Linux kernels with the affected serial 8250 driver on OMAP hardware or similar embedded platforms. The use-after-free condition can potentially be exploited to execute arbitrary code in kernel space or cause denial of service via kernel crashes, impacting system availability and integrity. Critical infrastructure, industrial control systems, telecommunications equipment, and embedded devices that rely on Linux with this driver are particularly at risk. While exploitation requires triggering the device removal under failure conditions, attackers with local access or the ability to manipulate device states could leverage this flaw. The impact on confidentiality is limited unless combined with other vulnerabilities to escalate privileges or extract sensitive data. However, the integrity and availability of affected systems could be compromised, leading to operational disruptions. Given the widespread use of Linux in European IT environments, especially in servers, IoT devices, and embedded systems, unpatched systems could face increased risk of targeted attacks or accidental failures.

Organizations should prioritize updating their Linux kernels to versions that include the patch for CVE-2023-52457. Since this vulnerability involves kernel-level driver code, applying vendor-supplied kernel updates or recompiling the kernel with the fix is essential. For embedded systems or devices where kernel updates are not straightforward, consider isolating affected hardware or disabling the affected serial ports if feasible. Monitoring system logs for unusual device removal errors or resource leaks can help detect attempts to exploit this vulnerability. Additionally, restricting local access to trusted users and employing kernel hardening techniques such as SELinux or AppArmor can reduce exploitation risk. For critical infrastructure, implementing network segmentation and limiting exposure of vulnerable devices to untrusted networks will further mitigate potential attacks. Finally, maintain an inventory of devices running affected kernel versions to ensure timely patch management.