kernel: mm/MADV_COLLAPSE: catch !none !huge !bad pmd lookups

In the Linux kernel, the following vulnerability has been resolved: mm/MADVCOLLAPSE: catch !none !huge !bad pmd lookups In commit 34488399fa08 "mm/madvise: add file and shmem support to MADVCOLLAPSE" we make the following change to findpmdorthpornone: - if !pmdpresentpmde - return SCANPMDNULL; + ...