CVE-2023-53719

Vulnerability

In the Linux kernel's arc_uart serial driver, the arc_serial_probe function allocates memory-mapped I/O resources using of_iomap(). However, if the subsequent uart_add_one_port() call fails, the allocated region pointed to by port->membase is not released, leading to a resource leak. This issue was identified by Smatch static analysis.

Attack

Vector

The vulnerability can be triggered when the arc_serial_probe function is invoked and uart_add_one_port() returns an error. An attacker with the ability to cause such a probe failure (e.g., by manipulating device tree entries or triggering hotplug events) could repeatedly trigger the leak, eventually exhausting the system's I/O memory resources.

Impact

Successful exploitation could lead to denial of service (DoS) by consuming all available memory-mapped I/O space, preventing other devices from claiming necessary resources. The leak does not provide code execution or privilege escalation.

Mitigation

The fix, backported to stable kernel releases [1][2][3], replaces the manual of_iomap() with the managed devm_platform_ioremap_resource(), which automatically frees the resource if the probe fails. Users should apply the latest stable kernel updates to address this vulnerability.