batman-adv: check return type of unicast packet preparations

batadv_unicast(_4addr)_prepare_skb  might reallocate the skb's data.
And if it tries to do so then this can potentially fail.

We shouldn't continue working on this skb in such a case.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Acked-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

1 files changed, 7 insertions, 3 deletions

diff --git a/net/batman-adv/unicast.c b/net/batman-adv/unicast.c
index 688a0419756b..857e1b8349ee 100644
--- a/net/batman-adv/unicast.c
+++ b/net/batman-adv/unicast.c
@@ -432,12 +432,16 @@ find_router:
 
         switch (packet_type) {
         case BATADV_UNICAST:
-                batadv_unicast_prepare_skb(skb, orig_node);
+                if (!batadv_unicast_prepare_skb(skb, orig_node))
+                        goto out;
+
                 header_len = sizeof(struct batadv_unicast_packet);
                 break;
         case BATADV_UNICAST_4ADDR:
-                batadv_unicast_4addr_prepare_skb(bat_priv, skb, orig_node,
-                                                 packet_subtype);
+                if (!batadv_unicast_4addr_prepare_skb(bat_priv, skb, orig_node,
+                                                      packet_subtype))
+                        goto out;
+
                 header_len = sizeof(struct batadv_unicast_4addr_packet);
                 break;
         default: