diff --git a/scst/include/scst.h b/scst/include/scst.h
index 31ac605ee..47162e3ff 100644
--- a/scst/include/scst.h
+++ b/scst/include/scst.h
@@ -2501,6 +2501,9 @@ struct scst_device {
 	/* List of blocked commands, protected by dev_lock. */
 	struct list_head blocked_cmd_list;
 
+	/* MAXIMUM WRITE SAME LENGTH in bytes */
+	uint64_t max_write_same_len;
+
 	/* A list entry used during TM */
 	struct list_head tm_dev_list_entry;
 
diff --git a/scst/src/dev_handlers/scst_vdisk.c b/scst/src/dev_handlers/scst_vdisk.c
index be0372a20..20fcba6d5 100644
--- a/scst/src/dev_handlers/scst_vdisk.c
+++ b/scst/src/dev_handlers/scst_vdisk.c
@@ -2558,8 +2558,9 @@ static enum compl_status_e vdisk_exec_inquiry(struct vdisk_cmd_params *p)
 				}
 			}
 
-			/* MAXIMUM WRITE SAME LENGTH (512MB) */
-			put_unaligned_be64((512*1024*1024) >> dev->block_shift, &buf[36]);
+			/* MAXIMUM WRITE SAME LENGTH (measured in blocks) */
+			put_unaligned_be64(dev->max_write_same_len >>
+					   dev->block_shift, &buf[36]);
 
 			resp_len = buf[3] + 4;
 		} else if ((0xB1 == cmd->cdb[2]) && (dev->type == TYPE_DISK)) {
diff --git a/scst/src/scst_lib.c b/scst/src/scst_lib.c
index 5a9bce286..4a698bd5f 100644
--- a/scst/src/scst_lib.c
+++ b/scst/src/scst_lib.c
@@ -4870,7 +4870,7 @@ void scst_write_same(struct scst_cmd *cmd)
 	}
 
 	if (cmd->sg_cnt != 1) {
-		PRINT_ERROR("WRITE SAME must contain only single block of data "
+		PRINT_WARNING("WRITE SAME must contain only single block of data "
 			"in a single SG (cmd %p)", cmd);
 		scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_parameter_value_invalid));
 		goto out_done;
@@ -4881,6 +4881,14 @@ void scst_write_same(struct scst_cmd *cmd)
 		goto out_done;
 	}
 
+	if (unlikely((uint64_t)cmd->data_len > cmd->dev->max_write_same_len)) {
+		PRINT_WARNING("Invalid WRITE SAME data len %lld (max allowed "
+			"%lld)", (long long)cmd->data_len,
+			(long long)cmd->dev->max_write_same_len);
+		scst_set_invalid_field_in_cdb(cmd, cmd->len_off, 0);
+		goto out_done;
+	}
+
 	wsp = kzalloc(sizeof(*wsp), GFP_KERNEL);
 	if (wsp == NULL) {
 		PRINT_ERROR("Unable to allocate ws_priv (size %zd, cmd %p)",
diff --git a/scst/src/scst_main.c b/scst/src/scst_main.c
index bdd27987e..a6bf13269 100644
--- a/scst/src/scst_main.c
+++ b/scst/src/scst_main.c
@@ -2080,6 +2080,7 @@ assign:
 
 	dev->threads_num = handler->threads_num;
 	dev->threads_pool_type = handler->threads_pool_type;
+	dev->max_write_same_len = 512 * 1024 * 1024; /* 512 MB */
 
 	if (handler->attach) {
 		TRACE_DBG("Calling new dev handler's attach(%p)", dev);