batman-adv: Make bat_priv->primary_if an rcu protected pointer
The rcu protected macros rcu_dereference() and rcu_assign_pointer()
for the bat_priv->primary_if need to be used, as well as spin/rcu locking.
Otherwise we might end up using a primary_if pointer pointing to already
freed memory.
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
diff --git a/net/batman-adv/unicast.c b/net/batman-adv/unicast.c
index d46acc8..b46cbf1 100644
--- a/net/batman-adv/unicast.c
+++ b/net/batman-adv/unicast.c
@@ -221,15 +221,17 @@
struct hard_iface *hard_iface, uint8_t dstaddr[])
{
struct unicast_packet tmp_uc, *unicast_packet;
+ struct hard_iface *primary_if;
struct sk_buff *frag_skb;
struct unicast_frag_packet *frag1, *frag2;
int uc_hdr_len = sizeof(struct unicast_packet);
int ucf_hdr_len = sizeof(struct unicast_frag_packet);
int data_len = skb->len - uc_hdr_len;
- int large_tail = 0;
+ int large_tail = 0, ret = NET_RX_DROP;
uint16_t seqno;
- if (!bat_priv->primary_if)
+ primary_if = primary_if_get_selected(bat_priv);
+ if (!primary_if)
goto dropped;
frag_skb = dev_alloc_skb(data_len - (data_len / 2) + ucf_hdr_len);
@@ -254,7 +256,7 @@
frag1->version = COMPAT_VERSION;
frag1->packet_type = BAT_UNICAST_FRAG;
- memcpy(frag1->orig, bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
+ memcpy(frag1->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
memcpy(frag2, frag1, sizeof(struct unicast_frag_packet));
if (data_len & 1)
@@ -269,13 +271,17 @@
send_skb_packet(skb, hard_iface, dstaddr);
send_skb_packet(frag_skb, hard_iface, dstaddr);
- return NET_RX_SUCCESS;
+ ret = NET_RX_SUCCESS;
+ goto out;
drop_frag:
kfree_skb(frag_skb);
dropped:
kfree_skb(skb);
- return NET_RX_DROP;
+out:
+ if (primary_if)
+ hardif_free_ref(primary_if);
+ return ret;
}
int unicast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv)