diff --git a/fs/buffer.c b/fs/buffer.c
index eeb8ac1aa8561f241ff007fcf3c4bd943ffffdb8..2a7828c0e59bc62b2b5f33a94ac3abcfdd3d8e38 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1042,8 +1042,21 @@ grow_buffers(struct block_device *bdev, sector_t block, int size)
 	} while ((size << sizebits) < PAGE_SIZE);
 
 	index = block >> sizebits;
-	block = index << sizebits;
 
+	/*
+	 * Check for a block which wants to lie outside our maximum possible
+	 * pagecache index.  (this comparison is done using sector_t types).
+	 */
+	if (unlikely(index != block >> sizebits)) {
+		char b[BDEVNAME_SIZE];
+
+		printk(KERN_ERR "%s: requested out-of-range block %llu for "
+			"device %s\n",
+			__FUNCTION__, (unsigned long long)block,
+			bdevname(bdev, b));
+		return -EIO;
+	}
+	block = index << sizebits;
 	/* Create a page with the proper size buffers.. */
 	page = grow_dev_page(bdev, block, index, size);
 	if (!page)
@@ -1070,12 +1083,16 @@ __getblk_slow(struct block_device *bdev, sector_t block, int size)
 
 	for (;;) {
 		struct buffer_head * bh;
+		int ret;
 
 		bh = __find_get_block(bdev, block, size);
 		if (bh)
 			return bh;
 
-		if (!grow_buffers(bdev, block, size))
+		ret = grow_buffers(bdev, block, size);
+		if (ret < 0)
+			return NULL;
+		if (ret == 0)
 			free_more_memory();
 	}
 }