From: Jue Wang <juew@xxxxxxxxxx>
Anon THP tails were already supported, but memory-failure may need to use
page_address_in_vma() on file THP tails, which its page->mapping check did
not permit: fix it.
hughd adds: no current usage is known to hit the issue, but this does fix
a subtle trap in a general helper: best fixed in stable sooner than later.
Fixes: 800d8c63b2e9 ("shmem: add huge pages support")
Signed-off-by: Jue Wang <juew@xxxxxxxxxx>
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
---
mm/rmap.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/mm/rmap.c b/mm/rmap.c
index 144de54efc1c..e05c300048e6 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -716,11 +716,11 @@ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
if (!vma->anon_vma || !page__anon_vma ||
vma->anon_vma->root != page__anon_vma->root)
return -EFAULT;
- } else if (page->mapping) {
- if (!vma->vm_file || vma->vm_file->f_mapping != page->mapping)
- return -EFAULT;
- } else
+ } else if (!vma->vm_file) {
+ return -EFAULT;
+ } else if (vma->vm_file->f_mapping != compound_head(page)->mapping) {
return -EFAULT;
+ }
return vma_address(page, vma);
}
--
2.32.0.rc0.204.g9fa02ecfa5-goog
