target: report too-small parameter lists everywhere

Several places were not checking that the parameter list length
was large enough, and thus accessing invalid memory.  Zero-length
parameter lists are just a special case of this.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index 1e94650..956c84c 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -1540,6 +1540,14 @@
 	tidh_new->dest_local_nexus = 1;
 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
 
+	if (cmd->data_length < 28) {
+		pr_warn("SPC-PR: Received PR OUT parameter list"
+			" length too small: %u\n", cmd->data_length);
+		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
+		ret = -EINVAL;
+		goto out;
+	}
+
 	buf = transport_kmap_data_sg(cmd);
 	/*
 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,