From: Miaohe Lin <[email protected]> [ Upstream commit 5d5d19eda6b0ee790af89c45e3f678345be6f50f ]
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]> Signed-off-by: Sasha Levin <[email protected]> --- include/linux/rmap.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 70085ca1a3fc9..def5c62c93b3b 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -213,7 +213,8 @@ struct page_vma_mapped_walk { static inline void page_vma_mapped_walk_done(struct page_vma_mapped_walk *pvmw) { - if (pvmw->pte) + /* HugeTLB pte is set to the relevant page table entry without pte_mapped. */ + if (pvmw->pte && !PageHuge(pvmw->page)) pte_unmap(pvmw->pte); if (pvmw->ptl) spin_unlock(pvmw->ptl); -- 2.27.0
