From: Jerome Glisse <jglisse@xxxxxxxxxx>
Do not increase page count if FOLL_GET is not set. None of the
current user can trigger the issue because none of the current
user call __get_user_pages with both the pages array ptr non
NULL and the FOLL_GET flags non set in other word all caller
of __get_user_pages that don't set the FOLL_GET flags also call
with pages == NULL.
v2: Do not use get_page_foll. Improved comment.
Signed-off-by: Jerome Glisse <jglisse@xxxxxxxxxx>
---
mm/hugetlb.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index ca9a7c6..32f323b 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2981,7 +2981,9 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
same_page:
if (pages) {
pages[i] = mem_map_offset(page, pfn_offset);
- get_page(pages[i]);
+ if (flags & FOLL_GET) {
+ get_page(pages[i]);
+ }
}
if (vmas)
--
1.7.11.7
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