diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
index 62d7a5661d..5f0ee9db00 100644
--- a/hw/block/pflash_cfi01.c
+++ b/hw/block/pflash_cfi01.c
@@ -707,6 +707,19 @@ static void pflash_cfi01_realize(DeviceState *dev, Error **errp)
     int num_devices;
     Error *local_err = NULL;
 
+    if (pfl->sector_len == 0) {
+        error_setg(errp, "attribute \"sector-length\" not specified or zero.");
+        return;
+    }
+    if (pfl->nb_blocs == 0) {
+        error_setg(errp, "attribute \"num-blocks\" not specified or zero.");
+        return;
+    }
+    if (pfl->name == NULL) {
+        error_setg(errp, "attribute \"name\" not specified.");
+        return;
+    }
+
     total_len = pfl->sector_len * pfl->nb_blocs;
 
     /* These are only used to expose the parameters of each device
diff --git a/hw/block/pflash_cfi02.c b/hw/block/pflash_cfi02.c
index 4f6105cc58..ef71322759 100644
--- a/hw/block/pflash_cfi02.c
+++ b/hw/block/pflash_cfi02.c
@@ -600,6 +600,19 @@ static void pflash_cfi02_realize(DeviceState *dev, Error **errp)
     int ret;
     Error *local_err = NULL;
 
+    if (pfl->sector_len == 0) {
+        error_setg(errp, "attribute \"sector-length\" not specified or zero.");
+        return;
+    }
+    if (pfl->nb_blocs == 0) {
+        error_setg(errp, "attribute \"num-blocks\" not specified or zero.");
+        return;
+    }
+    if (pfl->name == NULL) {
+        error_setg(errp, "attribute \"name\" not specified.");
+        return;
+    }
+
     chip_len = pfl->sector_len * pfl->nb_blocs;
     /* XXX: to be fixed */
 #if 0