[SCSI] ses: fix VPD inquiry overrun

There are a few kerneloops.org reports like this one:

http://www.kerneloops.org/search.php?search=ses_match_to_enclosure

That seem to imply we're running off the end of the VPD inquiry data
(although at 512 bytes, it should be long enough for just about
anything).  we should be using correctly sized buffers anyway, so put
those in and hope this oops goes away.

Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/ses.c

@@ -345,14 +345,14 @@ static int ses_enclosure_find_by_addr(struct enclosure_device *edev,
 	return 0;
 }
 
-#define VPD_INQUIRY_SIZE 512
+#define VPD_INQUIRY_SIZE 36
 
 static void ses_match_to_enclosure(struct enclosure_device *edev,
 				   struct scsi_device *sdev)
 {
 	unsigned char *buf = kmalloc(VPD_INQUIRY_SIZE, GFP_KERNEL);
 	unsigned char *desc;
-	int len;
+	u16 vpd_len;
 	struct efd efd = {
 		.addr = 0,
 	};
@@ -372,9 +372,19 @@ static void ses_match_to_enclosure(struct enclosure_device *edev,
 			     VPD_INQUIRY_SIZE, NULL, SES_TIMEOUT, SES_RETRIES))
 		goto free;
 
-	len = (buf[2] << 8) + buf[3];
+	vpd_len = (buf[2] << 8) + buf[3];
+	kfree(buf);
+	buf = kmalloc(vpd_len, GFP_KERNEL);
+	if (!buf)
+		return;
+	cmd[3] = vpd_len >> 8;
+	cmd[4] = vpd_len & 0xff;
+	if (scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf,
+			     vpd_len, NULL, SES_TIMEOUT, SES_RETRIES))
+		goto free;
+
 	desc = buf + 4;
-	while (desc < buf + len) {
+	while (desc < buf + vpd_len) {
 		enum scsi_protocol proto = desc[0] >> 4;
 		u8 code_set = desc[0] & 0x0f;
 		u8 piv = desc[1] & 0x80;