3.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Liu Bo <redacted>

commit cd857dd6bc2ae9ecea14e75a34e8a8fdc158e307 upstream.

We want to make sure the point is still within the extent item, not to verify
the memory it's pointing to.

Signed-off-by: Liu Bo <redacted>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/btrfs/backref.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c

@@ -1424,7 +1424,7 @@ static int __get_extent_inline_ref(unsig
 			*out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1);
 		}
 		*ptr = (unsigned long)*out_eiref;
-		if ((void *)*ptr >= (void *)ei + item_size)
+		if ((unsigned long)(*ptr) >= (unsigned long)ei + item_size)
 			return -ENOENT;
 	}