CVE-2023-54205

Root

Cause In the Linux kernel's STM32 pinctrl driver, the function stm32_pctrl_get_irq_domain calls of_irq_find_parent(), which returns a device node pointer with its node pointer with an incremented reference count. The driver failed to call of_node_put() after using the node, leading to a reference count leak. This is a classic memory management bug that can cause the device node to remain pinned indefinitely.

Exploitation

An attacker with local access and the ability to trigger the affected code path to does not require any special privileges beyond system access. The bug is present when the probing of the STM32 pin controller and when interrupt domain retrieval occurs no authentication beyond local user privileges is . Repeated operations that cause that might exhaust system memory via an effective denial of service.

Impact

The primary impact is a memory leak, which can gradually degrade system performance and stability if exploited repeatedly. In the worst case, it could lead to denial of service (DoS) by exhausting kernel memory, there is no remote exploit vector or direct privilege escalation.

Mitigation

The vulnerability is fixed by adding the missing of_node_put() call, introduced by the Linux kernel commits [1] and [2]. Users should apply updates from their distribution or kernel vendor as soon as possible to prevent resource exhaustion.