Refcount Leak in Apple AIC IRQ Chip of Linux Kernel

CVE-2022-49718

Summary

In the Linux kernel's Apple AIC IRQ chip implementation, a refcount leak occurs due to the improper management of node pointers returned by the of_get_child_by_name() function. When this function is called, it returns a node pointer with its reference count incremented, but there was an omission in utilizing of_node_put() to release the reference when it is no longer needed. This oversight can lead to memory leaks over time, potentially destabilizing systems that rely on this kernel functionality. The vulnerability has been addressed in subsequent releases with the addition of the necessary of_node_put() calls to ensure proper reference management.

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