NTFS: Fix a potential overflow by casting (index + 1) to s64 before doing a
left shift using PAGE_CACHE_SHIFT in fs/ntfs/file.c. Thanks to Andrew
Morton pointing this out to.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index 7275338..c73c886 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -248,7 +248,7 @@
* enough to make ntfs_writepage() work.
*/
write_lock_irqsave(&ni->size_lock, flags);
- ni->initialized_size = (index + 1) << PAGE_CACHE_SHIFT;
+ ni->initialized_size = (s64)(index + 1) << PAGE_CACHE_SHIFT;
if (ni->initialized_size > new_init_size)
ni->initialized_size = new_init_size;
write_unlock_irqrestore(&ni->size_lock, flags);