Linux Kernel Refcount Leak Vulnerability in DRM MSM A6XX Component

A refcount leak vulnerability has been identified in the Linux kernel's DRM MSM A6XX component. The issue arises in the 'a6xx_gpu_initof_parse_phandle()' function, which returns a node pointer with an incremented refcount. The 'a6xx_gmu_init()' function then passes this node to 'of_find_device_by_node()' and 'of_dma_configure()'. While 'of_find_device_by_node()' takes a reference to the node, 'of_dma_configure()' does not require the node after use. The vulnerability can be exploited by failing to release the node reference properly, leading to a refcount leak.

Impact

Exploitation of this vulnerability causes a refcount leak, which can lead to memory management issues such as use-after-free vulnerabilities or memory exhaustion.