From: Sven Eckelmann Date: Sat, 2 Jul 2016 09:52:13 +0200 Subject: [PATCH] batman-adv: Avoid nullptr dereference in bla after vlan_insert_tag vlan_insert_tag can return NULL on errors. The bridge loop avoidance code therefore has to check the return value of vlan_insert_tag for NULL before it can safely operate on this pointer. Fixes: a9ce0dc43e2c ("batman-adv: add basic bridge loop avoidance code") Signed-off-by: Sven Eckelmann Signed-off-by: Marek Lindner Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/e4cffba4d3353ea15287abbfbdd65208aa62c156 --- net/batman-adv/bridge_loop_avoidance.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index 748a9ea..7129780 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -418,9 +418,12 @@ static void batadv_bla_send_claim(struct batadv_priv *bat_priv, u8 *mac, break; } - if (vid & BATADV_VLAN_HAS_TAG) + if (vid & BATADV_VLAN_HAS_TAG) { skb = vlan_insert_tag(skb, htons(ETH_P_8021Q), vid & VLAN_VID_MASK); + if (!skb) + goto out; + } skb_reset_mac_header(skb); skb->protocol = eth_type_trans(skb, soft_iface);