diff --git a/grub-core/kern/file.c b/grub-core/kern/file.c
index 749e72dfc..2407e72c5 100644
--- a/grub-core/kern/file.c
+++ b/grub-core/kern/file.c
@@ -26,6 +26,7 @@
 #include <grub/device.h>
 
 grub_err_t (*grub_file_net_seek) (struct grub_file *file, grub_off_t offset) = NULL;
+void (*EXPORT_VAR (grub_grubnet_fini)) (void);
 
 grub_file_filter_t grub_file_filters_all[GRUB_FILE_FILTER_MAX];
 grub_file_filter_t grub_file_filters_enabled[GRUB_FILE_FILTER_MAX];
diff --git a/grub-core/kern/ieee1275/init.c b/grub-core/kern/ieee1275/init.c
index ad34ea188..3c55096a4 100644
--- a/grub-core/kern/ieee1275/init.c
+++ b/grub-core/kern/ieee1275/init.c
@@ -264,6 +264,8 @@ grub_machine_init (void)
 void
 grub_machine_fini (void)
 {
+  if (grub_grubnet_fini)
+    grub_grubnet_fini ();
   grub_ofdisk_fini ();
   grub_console_fini ();
 }
diff --git a/grub-core/net/arp.c b/grub-core/net/arp.c
index 1dbd8a58f..fecde3282 100644
--- a/grub-core/net/arp.c
+++ b/grub-core/net/arp.c
@@ -39,6 +39,7 @@ grub_net_arp_resolve (struct grub_net_network_level_interface *inf,
   struct arphdr *arp_header;
   grub_net_link_level_address_t target_hw_addr;
   char *aux, arp_data[128];
+  grub_err_t err;
   int i;
 
   if (proto_addr->type == GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4
@@ -60,9 +61,12 @@ grub_net_arp_resolve (struct grub_net_network_level_interface *inf,
   nb.head = arp_data;
   nb.end = arp_data + sizeof (arp_data);
   grub_netbuff_clear (&nb);
-
   grub_netbuff_reserve (&nb, 128);
-  grub_netbuff_push (&nb, sizeof (*arp_header) + 2 * (6 + 4));
+
+  err = grub_netbuff_push (&nb, sizeof (*arp_header) + 2 * (6 + 4));
+  if (err)
+    return err;
+
   arp_header = (struct arphdr *) nb.data;
   arp_header->hrd = grub_cpu_to_be16 (GRUB_NET_ARPHRD_ETHERNET);
   arp_header->pro = grub_cpu_to_be16 (GRUB_NET_ETHERTYPE_IP);
diff --git a/grub-core/net/drivers/ieee1275/ofnet.c b/grub-core/net/drivers/ieee1275/ofnet.c
index 751583e9d..2c264edb1 100644
--- a/grub-core/net/drivers/ieee1275/ofnet.c
+++ b/grub-core/net/drivers/ieee1275/ofnet.c
@@ -225,6 +225,13 @@ GRUB_MOD_INIT(ofnet)
 
 GRUB_MOD_FINI(ofnet)
 {
+  struct grub_net_card *card;
+  FOR_NET_CARDS (card) 
+    if (card->driver && !grub_strcmp (card->driver->name, "ofnet"))
+      {
+	card->driver->fini (card);
+	card->driver = NULL;
+      }
   grub_net_card_driver_unregister (&ofdriver);
   grub_getbootp = NULL;
 }
diff --git a/grub-core/net/ethernet.c b/grub-core/net/ethernet.c
index f1bc8c1d0..863e659a8 100644
--- a/grub-core/net/ethernet.c
+++ b/grub-core/net/ethernet.c
@@ -15,8 +15,11 @@ send_ethernet_packet (struct grub_net_network_level_interface *inf,
 		      grub_uint16_t ethertype)
 {
   struct etherhdr *eth;
+  grub_err_t err;
 
-  grub_netbuff_push (nb, sizeof (*eth));
+  err = grub_netbuff_push (nb, sizeof (*eth));
+  if (err)
+    return err;
   eth = (struct etherhdr *) nb->data;
   grub_memcpy (eth->dst, target_addr.mac, 6);
   grub_memcpy (eth->src, inf->hwaddress.mac, 6);
@@ -35,10 +38,13 @@ grub_net_recv_ethernet_packet (struct grub_net_buff * nb,
   struct snaphdr *snaph;
   grub_uint16_t type;
   grub_net_link_level_address_t hwaddress;
+  grub_err_t err;
 
   eth = (struct etherhdr *) nb->data;
   type = grub_be_to_cpu16 (eth->type);
-  grub_netbuff_pull (nb, sizeof (*eth));
+  err = grub_netbuff_pull (nb, sizeof (*eth));
+  if (err)
+    return err;
 
   if (type <= 1500)
     {
@@ -47,7 +53,9 @@ grub_net_recv_ethernet_packet (struct grub_net_buff * nb,
 
       if (llch->dsap == 0xaa && llch->ssap == 0xaa && llch->ctrl == 0x3)
 	{
-	  grub_netbuff_pull (nb, sizeof (*llch));
+	  err = grub_netbuff_pull (nb, sizeof (*llch));
+	  if (err)
+	    return err;
 	  snaph = (struct snaphdr *) nb->data;
 	  type = snaph->type;
 	}
diff --git a/grub-core/net/ip.c b/grub-core/net/ip.c
index 808532a4a..776937a6e 100644
--- a/grub-core/net/ip.c
+++ b/grub-core/net/ip.c
@@ -94,7 +94,9 @@ grub_net_recv_ip_packets (struct grub_net_buff * nb,
 	{
 	  struct udphdr *udph;
 	  udph = (struct udphdr *) nb->data;
-	  grub_netbuff_pull (nb, sizeof (*udph));
+	  err = grub_netbuff_pull (nb, sizeof (*udph));
+	  if (err)
+	    return err;
 	  if (grub_be_to_cpu16 (udph->dst) == 68)
 	    grub_net_process_dhcp (nb, card);
 	}
diff --git a/grub-core/net/net.c b/grub-core/net/net.c
index 2da60256c..5c7d00991 100644
--- a/grub-core/net/net.c
+++ b/grub-core/net/net.c
@@ -632,6 +632,16 @@ grub_net_open_real (const char *name)
   return NULL;
 }
 
+static grub_err_t
+grub_net_fs_dir (grub_device_t device, const char *path __attribute__ ((unused)),
+	       int (*hook) (const char *filename,
+			    const struct grub_dirhook_info *info) __attribute__ ((unused)))
+{
+  if (!device->net)
+    return grub_error (GRUB_ERR_BAD_FS, "invalid extent");
+  return GRUB_ERR_NONE;
+}
+
 static grub_err_t
 grub_net_fs_open (struct grub_file *file, const char *name)
 {
@@ -1224,11 +1234,20 @@ grub_cmd_bootp (struct grub_command *cmd __attribute__ ((unused)),
   return err;
 }
 
+static void
+grub_grubnet_fini_real (void)
+{
+  struct grub_net_card *card;
+
+  FOR_NET_CARDS (card)
+    if (card->driver)
+      card->driver->fini (card);
+}
 
 static struct grub_fs grub_net_fs =
   {
     .name = "netfs",
-    .dir = NULL,
+    .dir = grub_net_fs_dir,
     .open = grub_net_fs_open,
     .read = grub_net_fs_read,
     .close = grub_net_fs_close,
@@ -1273,6 +1292,7 @@ GRUB_MOD_INIT(net)
   grub_fs_register (&grub_net_fs);
   grub_net_open = grub_net_open_real;
   grub_file_net_seek = grub_net_seek_real;
+  grub_grubnet_fini = grub_grubnet_fini_real;
 }
 
 GRUB_MOD_FINI(net)
@@ -1288,4 +1308,5 @@ GRUB_MOD_FINI(net)
   grub_fs_unregister (&grub_net_fs);
   grub_net_open = NULL;
   grub_file_net_seek = NULL;
+  grub_grubnet_fini = NULL;
 }
diff --git a/grub-core/net/netbuff.c b/grub-core/net/netbuff.c
index aae2f4d8f..d20104ab0 100644
--- a/grub-core/net/netbuff.c
+++ b/grub-core/net/netbuff.c
@@ -95,12 +95,12 @@ grub_err_t
 grub_netbuff_free (struct grub_net_buff *nb)
 {
   grub_free (nb->head);
-  return 0;
+  return GRUB_ERR_NONE;
 }
 
 grub_err_t
 grub_netbuff_clear (struct grub_net_buff *nb)
 {
   nb->data = nb->tail = nb->head;
-  return 0;
+  return GRUB_ERR_NONE;
 }
diff --git a/grub-core/net/tftp.c b/grub-core/net/tftp.c
index 545862092..d0ed7c43a 100644
--- a/grub-core/net/tftp.c
+++ b/grub-core/net/tftp.c
@@ -34,7 +34,8 @@ tftp_open (struct grub_file *file, const char *filename)
   grub_netbuff_clear (&nb);
 
   grub_netbuff_reserve (&nb, 1500);
-  grub_netbuff_push (&nb, sizeof (*tftph));
+  if ((err = grub_netbuff_push (&nb, sizeof (*tftph))) != GRUB_ERR_NONE)
+    return err;
 
   tftph = (struct tftphdr *) nb.data;
 
@@ -67,8 +68,8 @@ tftp_open (struct grub_file *file, const char *filename)
   rrq += grub_strlen ("0") + 1;
   hdrlen = sizeof (tftph->opcode) + rrqlen;
 
-  grub_netbuff_unput (&nb, nb.tail - (nb.data + hdrlen));
-
+  if ((err = grub_netbuff_unput (&nb, nb.tail - (nb.data + hdrlen))) != GRUB_ERR_NONE)
+    return err;
   file->device->net->socket->out_port = TFTP_SERVER_PORT;
 
   err = grub_net_send_udp_packet (file->device->net->socket, &nb);
@@ -130,9 +131,9 @@ tftp_receive (grub_net_socket_t sock, struct grub_net_buff *nb)
       grub_netbuff_clear (nb);
       break;
     case TFTP_DATA:
-      grub_netbuff_pull (nb, sizeof (tftph->opcode) +
-			 sizeof (tftph->u.data.block));
-
+      if ((err = grub_netbuff_pull (nb, sizeof (tftph->opcode) +
+			 sizeof (tftph->u.data.block))) != GRUB_ERR_NONE)
+	return err;
       if (grub_be_to_cpu16 (tftph->u.data.block) == data->block + 1)
 	{
 	  data->block++;
@@ -141,7 +142,8 @@ tftp_receive (grub_net_socket_t sock, struct grub_net_buff *nb)
 	    sock->status = 2;
 	  /* Prevent garbage in broken cards.  */
 	  if (size > 1024)
-	    grub_netbuff_unput (nb, size - 1024);
+	    if ((err = grub_netbuff_unput (nb, size - 1024)) != GRUB_ERR_NONE)
+	      return err;
 	}
       else
 	grub_netbuff_clear (nb);
@@ -154,8 +156,10 @@ tftp_receive (grub_net_socket_t sock, struct grub_net_buff *nb)
     }
   grub_netbuff_clear (&nb_ack);
   grub_netbuff_reserve (&nb_ack, 128);
-  grub_netbuff_push (&nb_ack, sizeof (tftph->opcode)
-		     + sizeof (tftph->u.ack.block));
+  err = grub_netbuff_push (&nb_ack, sizeof (tftph->opcode)
+			   + sizeof (tftph->u.ack.block));
+  if (err)
+    return err;
 
   tftph = (struct tftphdr *) nb_ack.data;
   tftph->opcode = grub_cpu_to_be16 (TFTP_ACK);
diff --git a/grub-core/net/udp.c b/grub-core/net/udp.c
index cc7534ea1..95134c0cf 100644
--- a/grub-core/net/udp.c
+++ b/grub-core/net/udp.c
@@ -9,8 +9,11 @@ grub_net_send_udp_packet (const grub_net_socket_t socket,
 			  struct grub_net_buff *nb)
 {
   struct udphdr *udph;
+  grub_err_t err;
 
-  grub_netbuff_push (nb, sizeof (*udph));
+  err = grub_netbuff_push (nb, sizeof (*udph));
+  if (err)
+    return err;
 
   udph = (struct udphdr *) nb->data;
   udph->src = grub_cpu_to_be16 (socket->in_port);
diff --git a/include/grub/net.h b/include/grub/net.h
index 5d99cace3..068ccec41 100644
--- a/include/grub/net.h
+++ b/include/grub/net.h
@@ -242,6 +242,7 @@ typedef struct grub_net
 
 extern grub_net_t (*EXPORT_VAR (grub_net_open)) (const char *name);
 extern grub_err_t (*EXPORT_VAR (grub_file_net_seek)) (struct grub_file *file, grub_off_t offset);
+extern void (*EXPORT_VAR (grub_grubnet_fini)) (void);
 
 struct grub_net_network_level_interface
 {