batman-adv/patches/0015-batman-adv-Avoid-nullptr-dereference-in-bla-after-vl.patch

   1 From: Sven Eckelmann <sven@narfation.org>
   2 Date: Sat, 2 Jul 2016 09:52:13 +0200
   3 Subject: [PATCH] batman-adv: Avoid nullptr dereference in bla after vlan_insert_tag
   4
   5 vlan_insert_tag can return NULL on errors. The bridge loop avoidance 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: a9ce0dc43e2c ("batman-adv: add basic bridge loop avoidance code")
  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/e4cffba4d3353ea15287abbfbdd65208aa62c156
  14 ---
  15  net/batman-adv/bridge_loop_avoidance.c | 5 ++++-
  16  1 file changed, 4 insertions(+), 1 deletion(-)
  17
  18 diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c
  19 index 0a6c8b8..fe8b62f 100644
  20 --- a/net/batman-adv/bridge_loop_avoidance.c
  21 +++ b/net/batman-adv/bridge_loop_avoidance.c
  22 @@ -409,9 +409,12 @@ static void batadv_bla_send_claim(struct batadv_priv *bat_priv, u8 *mac,
  23                 break;
  24         }
  25
  26 -       if (vid & BATADV_VLAN_HAS_TAG)
  27 +       if (vid & BATADV_VLAN_HAS_TAG) {
  28                 skb = vlan_insert_tag(skb, htons(ETH_P_8021Q),
  29                                       vid & VLAN_VID_MASK);
  30 +               if (!skb)
  31 +                       goto out;
  32 +       }
  33
  34         skb_reset_mac_header(skb);
  35         skb->protocol = eth_type_trans(skb, soft_iface);