mm/mmap.c in the hugetlb kernel, when run on PowerPC systems, does not prevent stack expansion from entering into reserved kernel page memory, which allows local users to cause a denial of service (OOPS) via unspecified vectors.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.