diff mbox series

[4.9,1/3] batman-adv: update data pointers after skb_cow()

Message ID 20200317201540.23496-2-sven@narfation.org
State New
Headers show
Series [4.9,1/3] batman-adv: update data pointers after skb_cow() | expand

Commit Message

Sven Eckelmann March 17, 2020, 8:15 p.m. UTC 
From: Matthias Schiffer <mschiffer@universe-factory.net>

commit bc44b78157f621ff2a2618fe287a827bcb094ac4 upstream.

batadv_check_unicast_ttvn() calls skb_cow(), so pointers into the SKB data
must be (re)set after calling it. The ethhdr variable is dropped
altogether.

Fixes: 78fc6bbe0aca ("batman-adv: add UNICAST_4ADDR packet type")
Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
 net/batman-adv/routing.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index f9ffb1825f6d..19059ae26e51 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -930,7 +930,6 @@  int batadv_recv_unicast_packet(struct sk_buff *skb,
 	bool is4addr;
 
 	unicast_packet = (struct batadv_unicast_packet *)skb->data;
-	unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
 
 	is4addr = unicast_packet->packet_type == BATADV_UNICAST_4ADDR;
 	/* the caller function should have already pulled 2 bytes */
@@ -951,9 +950,13 @@  int batadv_recv_unicast_packet(struct sk_buff *skb,
 	if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size))
 		return NET_RX_DROP;
 
+	unicast_packet = (struct batadv_unicast_packet *)skb->data;
+
 	/* packet for me */
 	if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) {
 		if (is4addr) {
+			unicast_4addr_packet =
+				(struct batadv_unicast_4addr_packet *)skb->data;
 			subtype = unicast_4addr_packet->subtype;
 			batadv_dat_inc_counter(bat_priv, subtype);