Design/Logic Flaw

A parameter verification issue was discovered in Xen through 4.9.x. The function alloc_heap_pages allows callers to specify the first NUMA node that should be used for allocations through the memflags parameter; the node is extracted using the MEMF_get_node macro. While the function checks to see if the special constant NUMA_NO_NODE is specified, it otherwise does not handle the case where node >= MAX_NUMNODES. This allows an out-of-bounds access to an internal array.