mm/rmap: fix potential pte_unmap on an not mapped pte

For PMD-mapped page (usually THP), pvmw->pte is NULL.  For PTE-mapped THP,
pvmw->pte is mapped.  But for HugeTLB pages, pvmw->pte is not mapped and
set to the relevant page table entry.  So in page_vma_mapped_walk_done(),
we may do pte_unmap() for HugeTLB pte which is not mapped.  Fix this by
checking pvmw->page against PageHuge before trying to do pte_unmap().

Link: https://lkml.kernel.org/r/[email protected]
Fixes: ace71a19cec5 ("mm: introduce page_vma_mapped_walk()")
Signed-off-by: Hongxiang Lou <[email protected]>
Signed-off-by: Miaohe Lin <[email protected]>
Tested-by: Sedat Dilek <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Michel Lespinasse <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: Dmitry Safonov <[email protected]>
Cc: Brian Geffon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions