diff --git a/drivers/usb/storage/sddr09.c b/drivers/usb/storage/sddr09.c
index 760fe93..b8e7802 100644
--- a/drivers/usb/storage/sddr09.c
+++ b/drivers/usb/storage/sddr09.c
@@ -711,6 +711,13 @@
 	unsigned int len, index, offset;
 	int result;
 
+	// Figure out the initial LBA and page
+	lba = address >> info->blockshift;
+	page = (address & info->blockmask);
+	maxlba = info->capacity >> (info->pageshift + info->blockshift);
+	if (lba >= maxlba)
+		return -EIO;
+
 	// Since we only read in one block at a time, we have to create
 	// a bounce buffer and move the data a piece at a time between the
 	// bounce buffer and the actual transfer buffer.
@@ -722,11 +729,6 @@
 		return -ENOMEM;
 	}
 
-	// Figure out the initial LBA and page
-	lba = address >> info->blockshift;
-	page = (address & info->blockmask);
-	maxlba = info->capacity >> (info->pageshift + info->blockshift);
-
 	// This could be made much more efficient by checking for
 	// contiguous LBA's. Another exercise left to the student.
 
@@ -928,13 +930,20 @@
 		  unsigned int sectors) {
 
 	struct sddr09_card_info *info = (struct sddr09_card_info *) us->extra;
-	unsigned int lba, page, pages;
+	unsigned int lba, maxlba, page, pages;
 	unsigned int pagelen, blocklen;
 	unsigned char *blockbuffer;
 	unsigned char *buffer;
 	unsigned int len, index, offset;
 	int result;
 
+	// Figure out the initial LBA and page
+	lba = address >> info->blockshift;
+	page = (address & info->blockmask);
+	maxlba = info->capacity >> (info->pageshift + info->blockshift);
+	if (lba >= maxlba)
+		return -EIO;
+
 	// blockbuffer is used for reading in the old data, overwriting
 	// with the new data, and performing ECC calculations
 
@@ -961,10 +970,6 @@
 		return -ENOMEM;
 	}
 
-	// Figure out the initial LBA and page
-	lba = address >> info->blockshift;
-	page = (address & info->blockmask);
-
 	result = 0;
 	index = offset = 0;
 
@@ -975,6 +980,14 @@
 		pages = min(sectors, info->blocksize - page);
 		len = (pages << info->pageshift);
 
+		/* Not overflowing capacity? */
+		if (lba >= maxlba) {
+			US_DEBUGP("Error: Requested lba %u exceeds "
+				  "maximum %u\n", lba, maxlba);
+			result = -EIO;
+			break;
+		}
+
 		// Get the data from the transfer buffer
 		usb_stor_access_xfer_buf(buffer, len, us->srb,
 				&index, &offset, FROM_XFER_BUF);