+ mm-hugetlb-alloc-the-vmemmap-pages-associated-with-each-hugetlb-page-fix.patch added to -mm tree

+ mm-hugetlb-alloc-the-vmemmap-pages-associated-with-each-hugetlb-page-fix.patch added to -mm tree

[akpm]

The patch titled
     Subject: mm: hugetlb: fix dissolve_free_huge_page use of tail/head page
has been added to the -mm tree.  Its filename is
     mm-hugetlb-alloc-the-vmemmap-pages-associated-with-each-hugetlb-page-fix.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-hugetlb-alloc-the-vmemmap-pages-associated-with-each-hugetlb-page-fix.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-hugetlb-alloc-the-vmemmap-pages-associated-with-each-hugetlb-page-fix.patch

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------------------------------------------------------
From: Mike Kravetz <mike.kravetz@oracle.com>
Subject: mm: hugetlb: fix dissolve_free_huge_page use of tail/head page

The routine dissolve_free_huge_page can be passed the tail page of a
hugetlb page.  The tail page is incorrectly passed on to the routines
alloc_huge_page_vmemmap and add_hugetlb_page which expect a hugetlb head
page.

Operating on a tail page instead of head page could result in addressing
exceptions or vmemmap corruption.

Link: https://lkml.kernel.org/r/20210527231225.226987-1-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/hugetlb.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/mm/hugetlb.c~mm-hugetlb-alloc-the-vmemmap-pages-associated-with-each-hugetlb-page-fix
+++ a/mm/hugetlb.c
@@ -1954,7 +1954,7 @@ retry:
 		 * Attempt to allocate vmemmmap here so that we can take
 		 * appropriate action on failure.
 		 */
-		rc = alloc_huge_page_vmemmap(h, page);
+		rc = alloc_huge_page_vmemmap(h, head);
 		if (!rc) {
 			/*
 			 * Move PageHWPoison flag from head page to the raw
@@ -1968,7 +1968,7 @@ retry:
 			update_and_free_page(h, head, false);
 		} else {
 			spin_lock_irq(&hugetlb_lock);
-			add_hugetlb_page(h, page, false);
+			add_hugetlb_page(h, head, false);
 			h->max_huge_pages++;
 			spin_unlock_irq(&hugetlb_lock);
 		}
_

Patches currently in -mm which might be from mike.kravetz@oracle.com are

mm-hugetlb-alloc-the-vmemmap-pages-associated-with-each-hugetlb-page-fix.patch