| Message ID | 20230913201248.452081-3-zi.yan@sent.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Use nth_page() in place of direct struct page manipulation | expand |
On 13 Sep 2023, at 16:12, Zi Yan wrote: > From: Zi Yan <ziy@nvidia.com> > > When dealing with hugetlb pages, manipulating struct page pointers > directly can get to wrong struct page, since struct page is not guaranteed > to be contiguous on SPARSEMEM without VMEMMAP. Use nth_page() to handle > it properly. > > Fixes: 57a196a58421 ("hugetlb: simplify hugetlb handling in follow_page_mask") > Cc: <stable@vger.kernel.org> > Signed-off-by: Zi Yan <ziy@nvidia.com> > Reviewed-by: Muchun Song <songmuchun@bytedance.com> > --- > mm/hugetlb.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index af74e83d92aa..8e68e6c53e66 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -6469,7 +6469,7 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma, > } > } > > - page += ((address & ~huge_page_mask(h)) >> PAGE_SHIFT); > + page = nth_page(page, ((address & ~huge_page_mask(h)) >> PAGE_SHIFT)); > > /* > * Note that page may be a sub-page, and with vmemmap > -- > 2.40.1 A wrong or non-existing page might be tried to be grabbed, either leading to a non freeable page or kernel memory access errors. No bug is reported. It comes from code inspection. -- Best Regards, Yan, Zi
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index af74e83d92aa..8e68e6c53e66 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -6469,7 +6469,7 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma, } } - page += ((address & ~huge_page_mask(h)) >> PAGE_SHIFT); + page = nth_page(page, ((address & ~huge_page_mask(h)) >> PAGE_SHIFT)); /* * Note that page may be a sub-page, and with vmemmap