diff --git a/fs/mpage.c b/fs/mpage.c
index 334e7d09aa65..ed00b3759ecc 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -186,9 +186,16 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args)
 	if (page_has_buffers(page))
 		goto confused;
 
+	if ((PAGE_SHIFT - blkbits) < 0)
+		goto confused;
+
+	if ((PAGE_SHIFT - blkbits) > sizeof(page->index))
+		goto confused;
+
 	block_in_file = (sector_t)page->index << (PAGE_SHIFT - blkbits);
 	last_block = block_in_file + args->nr_pages * blocks_per_page;
 	last_block_in_file = (i_size_read(inode) + blocksize - 1) >> blkbits;
+
 	if (last_block > last_block_in_file)
 		last_block = last_block_in_file;
 	page_block = 0;