On architectures where ssize_t is wider than pgoff_t, the expression
((page->index + 1) << PAGE_SHIFT) can overflow. Rewrite to use the page
offset, which we already compute here anyway.
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
---
fs/iomap/buffered-io.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index e25901ae3ff4..a30ea7ecb790 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1040,20 +1040,19 @@ vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops)
lock_page(page);
size = i_size_read(inode);
- if ((page->mapping != inode->i_mapping) ||
- (page_offset(page) > size)) {
+ offset = page_offset(page);
+ if (page->mapping != inode->i_mapping || offset > size) {
/* We overload EFAULT to mean page got truncated */
ret = -EFAULT;
goto out_unlock;
}
/* page is wholly or partially inside EOF */
- if (((page->index + 1) << PAGE_SHIFT) > size)
+ if (offset > size - PAGE_SIZE)
length = offset_in_page(size);
else
length = PAGE_SIZE;
- offset = page_offset(page);
while (length > 0) {
ret = iomap_apply(inode, offset, length,
IOMAP_WRITE | IOMAP_FAULT, ops, page,
--
2.20.1
