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authorFan Yang <Fan_Yang@sjtu.edu.cn>2020-06-04 13:22:07 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-06-11 10:22:57 +0300
commit469ef673629d36d8ed5912b52f5d87ecc0309b3c (patch)
tree6e44fe920767c00f94169ef089d0584f3d1d071a /mm/mremap.c
parent9a77644c9295a3c4248b1e070d9ce509ead838c0 (diff)
downloadlinux-469ef673629d36d8ed5912b52f5d87ecc0309b3c.tar.xz
mm: Fix mremap not considering huge pmd devmap
commit 5bfea2d9b17f1034a68147a8b03b9789af5700f9 upstream. The original code in mm/mremap.c checks huge pmd by: if (is_swap_pmd(*old_pmd) || pmd_trans_huge(*old_pmd)) { However, a DAX mapped nvdimm is mapped as huge page (by default) but it is not transparent huge page (_PAGE_PSE | PAGE_DEVMAP). This commit changes the condition to include the case. This addresses CVE-2020-10757. Fixes: 5c7fb56e5e3f ("mm, dax: dax-pmd vs thp-pmd vs hugetlbfs-pmd") Cc: <stable@vger.kernel.org> Reported-by: Fan Yang <Fan_Yang@sjtu.edu.cn> Signed-off-by: Fan Yang <Fan_Yang@sjtu.edu.cn> Tested-by: Fan Yang <Fan_Yang@sjtu.edu.cn> Tested-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm/mremap.c')
-rw-r--r--mm/mremap.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/mremap.c b/mm/mremap.c
index 88ceeb4ef817..3c7fcd5d5794 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -223,7 +223,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
new_pmd = alloc_new_pmd(vma->vm_mm, vma, new_addr);
if (!new_pmd)
break;
- if (is_swap_pmd(*old_pmd) || pmd_trans_huge(*old_pmd)) {
+ if (is_swap_pmd(*old_pmd) || pmd_trans_huge(*old_pmd) || pmd_devmap(*old_pmd)) {
if (extent == HPAGE_PMD_SIZE) {
bool moved;
/* See comment in move_ptes() */