diff --git a/stand/common/disk.c b/stand/common/disk.c
--- a/stand/common/disk.c
+++ b/stand/common/disk.c
@@ -468,7 +468,7 @@
 
 	if (*cp != '\0' && *cp != ':')
 		return (EINVAL);
-	dev = malloc(sizeof(*dev));
+	dev = calloc(sizeof(*dev), 1);
 	if (dev == NULL)
 		return (ENOMEM);
 	dev->dd.d_unit = unit;
diff --git a/stand/kboot/kboot/hostdisk.c b/stand/kboot/kboot/hostdisk.c
--- a/stand/kboot/kboot/hostdisk.c
+++ b/stand/kboot/kboot/hostdisk.c
@@ -465,7 +465,7 @@
 		return (EINVAL);
 	}
 	free(fn);
-	dev = malloc(sizeof(*dev));
+	dev = calloc(sizeof(*dev), 1);
 	if (dev == NULL)
 		return (ENOMEM);
 	dev->d_unit = 0;
diff --git a/stand/libofw/devicename.c b/stand/libofw/devicename.c
--- a/stand/libofw/devicename.c
+++ b/stand/libofw/devicename.c
@@ -98,7 +98,7 @@
 
 	if (ofw_path_to_handle(devspec, ofwtype, &rem_path) == -1)
 		return (ENOENT);
-	idev = malloc(sizeof(struct ofw_devdesc));
+	idev = calloc(sizeof(struct ofw_devdesc), 1);
 	if (idev == NULL) {
 		printf("ofw_parsedev: malloc failed\n");
 		return (ENOMEM);
diff --git a/stand/libsa/dev.c b/stand/libsa/dev.c
--- a/stand/libsa/dev.c
+++ b/stand/libsa/dev.c
@@ -72,7 +72,7 @@
 	int unit, err;
 	char *cp;
 
-	idev = malloc(sizeof(struct devdesc));
+	idev = calloc(sizeof(struct devdesc), 1);
 	if (idev == NULL)
 		return (ENOMEM);
 
diff --git a/stand/libsa/zfs/zfs.c b/stand/libsa/zfs/zfs.c
--- a/stand/libsa/zfs/zfs.c
+++ b/stand/libsa/zfs/zfs.c
@@ -1643,7 +1643,7 @@
 	spa = spa_find_by_name(poolname);
 	if (!spa)
 		return (ENXIO);
-	dev = malloc(sizeof(*dev));
+	dev = calloc(sizeof(*dev), 1);
 	if (dev == NULL)
 		return (ENOMEM);
 	dev->pool_guid = spa->spa_guid;
diff --git a/stand/uboot/devicename.c b/stand/uboot/devicename.c
--- a/stand/uboot/devicename.c
+++ b/stand/uboot/devicename.c
@@ -102,7 +102,7 @@
 	}
 	if (dv == NULL)
 		return(ENOENT);
-	idev = malloc(sizeof(struct uboot_devdesc));
+	idev = calloc(sizeof(struct uboot_devdesc), 1);
 	err = 0;
 	np = (devspec + strlen(dv->dv_name));