Linux Kernel Refcount Leak Vulnerability in IRQ Chip Handling

A refcount leak vulnerability has been identified in the Linux kernel's IRQ chip management. The issue arises in the 'platform_irqchip_probe' function, where the 'of_irq_find_parent' call returns a pointer to a device node with an incremented reference count. If this pointer is not properly released using 'of_node_put' when no longer needed, it creates a memory leak. The vulnerability affects the Linux kernel stable tree.

Impact

The vulnerability leads to a memory leak, where reference counts are not properly managed, potentially causing increased memory usage over time.

Reproduction

The vulnerability can be reproduced by invoking the 'platform_irqchip_probe' function without properly handling the reference count of the device node returned by 'of_irq_find_parent'. This can be done by not calling 'of_node_put' when the node is no longer needed, allowing the refcount to leak.

Remediation

The vulnerability has been addressed by adding the missing 'of_node_put' calls to properly manage the reference count and prevent the leak. Users can apply the latest patches available in the Linux kernel stable tree to remediate this issue.