diff --git a/src/platform/nm-fake-platform.c b/src/platform/nm-fake-platform.c
index 7b5450769..b0d441150 100644
--- a/src/platform/nm-fake-platform.c
+++ b/src/platform/nm-fake-platform.c
@@ -709,12 +709,13 @@ static gboolean
 infiniband_partition_add (NMPlatform *platform, int parent, int p_key, const NMPlatformLink **out_link)
 {
 	NMFakePlatformLink *device, *parent_device;
-	gs_free char *name = NULL;
+	char name[IFNAMSIZ];
 
 	parent_device = link_get (platform, parent);
 	g_return_val_if_fail (parent_device != NULL, FALSE);
 
-	name = g_strdup_printf ("%s.%04x", parent_device->link.name, p_key);
+	nm_utils_new_infiniband_name (name, parent_device->link.name, p_key);
+
 	if (!link_add (platform, name, NM_LINK_TYPE_INFINIBAND, NULL, 0, out_link))
 		return FALSE;
 
@@ -726,7 +727,6 @@ infiniband_partition_add (NMPlatform *platform, int parent, int p_key, const NMP
 	device->lnk->lnk_infiniband.p_key = p_key;
 	device->lnk->lnk_infiniband.mode = "datagram";
 	device->link.parent = parent;
-
 	return TRUE;
 }
 
@@ -739,7 +739,7 @@ infiniband_partition_delete (NMPlatform *platform, int parent, int p_key)
 	parent_device = link_get (platform, parent);
 	g_return_val_if_fail (parent_device != NULL, FALSE);
 
-	name = g_strdup_printf ("%s.%04x", parent_device->link.name, p_key);
+	nm_utils_new_infiniband_name (name, parent_device->link.name, p_key);
 	return link_delete (platform, nm_platform_link_get_ifindex (platform, name));
 }
 
diff --git a/src/platform/nm-linux-platform.c b/src/platform/nm-linux-platform.c
index ab2c440f0..529d1dd2d 100644
--- a/src/platform/nm-linux-platform.c
+++ b/src/platform/nm-linux-platform.c
@@ -5100,7 +5100,7 @@ link_release (NMPlatform *platform, int master, int slave)
 /******************************************************************/
 
 static gboolean
-_infiniband_partition_action (NMPlatform *platform, int parent, int p_key, const char *action, char **ifname)
+_infiniband_partition_action (NMPlatform *platform, int parent, int p_key, const char *action, char *out_partition_name)
 {
 	NMLinuxPlatformPrivate *priv = NM_LINUX_PLATFORM_GET_PRIVATE (platform);
 	const NMPObject *obj_parent;
@@ -5110,10 +5110,13 @@ _infiniband_partition_action (NMPlatform *platform, int parent, int p_key, const
 	nm_assert (p_key > 0 && p_key <= 0xffff && p_key != 0x8000);
 
 	obj_parent = nmp_cache_lookup_link (priv->cache, parent);
-	if (!obj_parent || !obj_parent->link.name[0])
-		g_return_val_if_reached (FALSE);
+	if (!obj_parent || !obj_parent->link.name[0]) {
+		errno = ENOENT;
+		return FALSE;
+	}
 
-	*ifname = g_strdup_printf ("%s.%04x", obj_parent->link.name, p_key);
+	if (out_partition_name)
+		nm_utils_new_infiniband_name (out_partition_name, obj_parent->link.name, p_key);
 
 	path = g_strdup_printf ("/sys/class/net/%s/%s",
 	                        NM_ASSERT_VALID_PATH_COMPONENT (obj_parent->link.name),
@@ -5128,15 +5131,15 @@ static gboolean
 infiniband_partition_add (NMPlatform *platform, int parent, int p_key, const NMPlatformLink **out_link)
 {
 	const NMPObject *obj;
-	gs_free char *ifname = NULL;
+	char name[IFNAMSIZ];
 
-	if (!_infiniband_partition_action (platform, parent, p_key, "create_child", &ifname))
+	if (!_infiniband_partition_action (platform, parent, p_key, "create_child", name))
 		return FALSE;
 
-	do_request_link (platform, 0, ifname);
+	do_request_link (platform, 0, name);
 
 	obj = nmp_cache_lookup_link_full (NM_LINUX_PLATFORM_GET_PRIVATE (platform)->cache,
-	                                  0, ifname, FALSE, NM_LINK_TYPE_INFINIBAND, NULL, NULL);
+	                                  0, name, FALSE, NM_LINK_TYPE_INFINIBAND, NULL, NULL);
 	if (out_link)
 		*out_link = obj ? &obj->link : NULL;
 	return !!obj;
@@ -5145,9 +5148,7 @@ infiniband_partition_add (NMPlatform *platform, int parent, int p_key, const NMP
 static gboolean
 infiniband_partition_delete (NMPlatform *platform, int parent, int p_key)
 {
-	gs_free char *ifname = NULL;
-
-	if (!_infiniband_partition_action (platform, parent, p_key, "delete_child", &ifname)) {
+	if (!_infiniband_partition_action (platform, parent, p_key, "delete_child", NULL)) {
 		if (errno != ENODEV)
 			return FALSE;
 	}
diff --git a/src/platform/nm-platform.c b/src/platform/nm-platform.c
index 43532ebf3..58c54cb9a 100644
--- a/src/platform/nm-platform.c
+++ b/src/platform/nm-platform.c
@@ -1895,7 +1895,7 @@ _infiniband_add_add_or_delete (NMPlatform *self,
                                gboolean add,
                                const NMPlatformLink **out_link)
 {
-	gs_free char *name = NULL;
+	char name[IFNAMSIZ];
 	const NMPlatformLink *parent_link;
 	NMPlatformError plerr;
 
@@ -1915,7 +1915,7 @@ _infiniband_add_add_or_delete (NMPlatform *self,
 	if (parent_link->type != NM_LINK_TYPE_INFINIBAND)
 		return NM_PLATFORM_ERROR_WRONG_TYPE;
 
-	name = g_strdup_printf ("%s.%04x", parent_link->name, p_key);
+	nm_utils_new_infiniband_name (name, parent_link->name, p_key);
 
 	if (add) {
 		plerr = _link_add_check_existing (self, name, NM_LINK_TYPE_INFINIBAND, out_link);