Linux Kernel Null Pointer Dereference Vulnerability in IOMMU/ARM-SMMU

A null pointer dereference vulnerability has been identified in the Linux kernel's IOMMU/ARM-SMMU component. The issue arises in the 'arm_smmu_device_probe()' function when 'platform_get_resource()' returns NULL. This can lead to a null pointer dereference when the 'res' variable is used. The vulnerability has been addressed by modifying the code to use 'res' only after 'devm_ioremap_resource()' has checked it, and by employing 'devm_platform_get_and_ioremap_resource()' to streamline the code.

Impact

Exploitation of this vulnerability can lead to a null pointer dereference, causing a crash or undefined behavior in the kernel.