target: Fix trailing ASCII space usage in INQUIRY vendor+model

commit ee60bddb upstream.

This patch fixes spc_emulate_inquiry_std() to add trailing ASCII
spaces for INQUIRY vendor + model fields following SPC-4 text:

  "ASCII data fields described as being left-aligned shall have any
   unused bytes at the end of the field (i.e., highest offset) and
   the unused bytes shall be filled with ASCII space characters (20h)."

This addresses a problem with Falconstor NSS multipathing.
Reported-by: Tomas Molota <tomas.molota@lightstorm.sk>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
[bwh: Backported to 3.2, based on Nicholas's versions for 3.0 and 3.4]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/target/target_core_cdb.c

@@ -127,11 +127,12 @@ target_emulate_inquiry_std(struct se_cmd *cmd)
 		goto out;
 	}
 
-	snprintf((unsigned char *)&buf[8], 8, "LIO-ORG");
-	snprintf((unsigned char *)&buf[16], 16, "%s",
-		 &dev->se_sub_dev->t10_wwn.model[0]);
-	snprintf((unsigned char *)&buf[32], 4, "%s",
-		 &dev->se_sub_dev->t10_wwn.revision[0]);
+	memcpy(&buf[8], "LIO-ORG ", 8);
+	memset(&buf[16], 0x20, 16);
+	memcpy(&buf[16], dev->se_sub_dev->t10_wwn.model,
+	       min_t(size_t, strlen(dev->se_sub_dev->t10_wwn.model), 16));
+	memcpy(&buf[32], dev->se_sub_dev->t10_wwn.revision,
+	       min_t(size_t, strlen(dev->se_sub_dev->t10_wwn.revision), 4));
 	buf[4] = 31; /* Set additional length to 31 */
 
 out: