batman-adv/patches/0002-batman-adv-Avoid-nullptr-dereference-in-dat-after-vl.patch

   1 From: Sven Eckelmann <sven@narfation.org>
   2 Date: Sat, 2 Jul 2016 09:52:14 +0200
   3 Subject: [PATCH] batman-adv: Avoid nullptr dereference in dat after vlan_insert_tag
   4
   5 vlan_insert_tag can return NULL on errors. The distributed arp table code
   6 therefore has to check the return value of vlan_insert_tag for NULL before
   7 it can safely operate on this pointer.
   8
   9 Fixes: 53c6c262a581 ("batman-adv: tag locally generated ARP reply if needed")
  10 Signed-off-by: Sven Eckelmann <sven@narfation.org>
  11 Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
  12
  13 Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/898382d11fa1f737cd4f7033db1088c601fd11ed
  14 ---
  15  net/batman-adv/distributed-arp-table.c | 10 ++++++++--
  16  1 file changed, 8 insertions(+), 2 deletions(-)
  17
  18 diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
  19 index 278800a..aee3b39 100644
  20 --- a/net/batman-adv/distributed-arp-table.c
  21 +++ b/net/batman-adv/distributed-arp-table.c
  22 @@ -1009,9 +1009,12 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
  23                 if (!skb_new)
  24                         goto out;
  25
  26 -               if (vid & BATADV_VLAN_HAS_TAG)
  27 +               if (vid & BATADV_VLAN_HAS_TAG) {
  28                         skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
  29                                                   vid & VLAN_VID_MASK);
  30 +                       if (!skb_new)
  31 +                               goto out;
  32 +               }
  33
  34                 skb_reset_mac_header(skb_new);
  35                 skb_new->protocol = eth_type_trans(skb_new,
  36 @@ -1089,9 +1092,12 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
  37          */
  38         skb_reset_mac_header(skb_new);
  39
  40 -       if (vid & BATADV_VLAN_HAS_TAG)
  41 +       if (vid & BATADV_VLAN_HAS_TAG) {
  42                 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
  43                                           vid & VLAN_VID_MASK);
  44 +               if (!skb_new)
  45 +                       goto out;
  46 +       }
  47
  48         /* To preserve backwards compatibility, the node has choose the outgoing
  49          * format based on the incoming request packet type. The assumption is