From: Liu Shixin <liushixin2@huawei.com> hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I641XX CVE: NA -------------------------------- Patch 1378a5ee451a ("mm: store compound_nr as well as compound_order") add a new member compound_nr in struct page, and use this new member insteal of compound_order in hugetlb_cgroup_move_parent() to compute the nr_pages. In free_hugepage_to_hugetlb(), we reset page->mapping to NULL for each subpage. Since page->mapping and page->compound_nr is union, we reset page->compound_nr too unexpectly. This will finally result the nr_pages incorrect in hugetlb_cgroup_move_parent() and can't release hugetlb_cgroup. Fix this problem by reset page->compound_nr using set_compound_order(). Signed-off-by: Liu Shixin <liushixin2@huawei.com> Reviewed-by: Nanyong Sun <sunnanyong@huawei.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- mm/dynamic_hugetlb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/dynamic_hugetlb.c b/mm/dynamic_hugetlb.c index eb9b528b73de..8a985d816c07 100644 --- a/mm/dynamic_hugetlb.c +++ b/mm/dynamic_hugetlb.c @@ -799,7 +799,8 @@ static int free_hugepage_to_hugetlb(struct dhugetlb_pool *hpool) p->mapping = NULL; } set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); - + /* compound_nr and mapping are union in page, reset it. */ + set_compound_order(page, PUD_SHIFT - PAGE_SHIFT); nid = page_to_nid(page); SetHPageFreed(page); list_move(&page->lru, &h->hugepage_freelists[nid]); -- 2.20.1