The patch titled Subject: mm/rmap: fix potential pte_unmap on an not mapped pte has been added to the -mm tree. Its filename is mm-rmap-fix-potential-pte_unmap-on-an-not-mapped-pte.patch

This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-rmap-fix-potential-pte_unmap-on... and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-rmap-fix-potential-pte_unmap-on...

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------------------------------------------------------ From: Miaohe Lin linmiaohe@huawei.com Subject: 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/20210127093349.39081-1-linmiaohe@huawei.com Fixes: ace71a19cec5 ("mm: introduce page_vma_mapped_walk()") Signed-off-by: Hongxiang Lou louhongxiang@huawei.com Signed-off-by: Miaohe Lin linmiaohe@huawei.com Cc: Mike Kravetz mike.kravetz@oracle.com Cc: Shakeel Butt shakeelb@google.com Cc: Johannes Weiner hannes@cmpxchg.org Cc: Vlastimil Babka vbabka@suse.cz Cc: Michel Lespinasse walken@google.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

include/linux/rmap.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/include/linux/rmap.h~mm-rmap-fix-potential-pte_unmap-on-an-not-mapped-pte +++ a/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); _

Patches currently in -mm which might be from linmiaohe@huawei.com are

mm-rmap-fix-potential-pte_unmap-on-an-not-mapped-pte.patch mm-page_owner-use-helper-function-zone_end_pfn-to-get-end_pfn.patch mm-fix-potential-pte_unmap_unlock-pte-error.patch mm-hugetlb-fix-potential-double-free-in-hugetlb_register_node-error-path.patch mm-hugetlb-avoid-unnecessary-hugetlb_acct_memory-call.patch mm-hugetlb-use-helper-huge_page_order-and-pages_per_huge_page.patch mm-hugetlb-fix-use-after-free-when-subpool-max_hpages-accounting-is-not-enabled.patch mm-workingsetc-avoid-unnecessary-max_nodes-estimation-in-count_shadow_nodes.patch z3fold-remove-unused-attribute-for-release_z3fold_page.patch z3fold-simplify-the-zhdr-initialization-code-in-init_z3fold_page.patch mm-compaction-remove-duplicated-vm_bug_on_page-pagelocked.patch hugetlbfs-remove-useless-bug_oninode-in-hugetlbfs_setattr.patch hugetlbfs-use-helper-macro-default_hstate-in-init_hugetlbfs_fs.patch hugetlbfs-correct-obsolete-function-name-in-hugetlbfs_read_iter.patch hugetlbfs-remove-meaningless-variable-avoid_reserve.patch hugetlbfs-make-hugepage-size-conversion-more-readable.patch hugetlbfs-correct-some-obsolete-comments-about-inode-i_mutex.patch mm-memory_hotplug-use-helper-function-zone_end_pfn-to-get-end_pfn.patch mm-rmap-correct-some-obsolete-comments-of-anon_vma.patch mm-zsmallocc-convert-to-use-kmem_cache_zalloc-in-cache_alloc_zspage.patch