mm/mempolicy: fix memory leak in set_mempolicy_home_node system call

In the Linux kernel, the following vulnerability has been resolved: mm/mempolicy: fix memory leak in set_mempolicy_home_node system call When encountering any vma in the range with policy other than MPOL_BIND or MPOL_PREFERRED_MANY, an error is returned without issuing a mpol_put on the policy just allocated with mpol_dup(). This allows arbitrary users to leak kernel memory.