From 95917cc978704ba57870bda367afa334ddc00a7e Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Fri, 16 Mar 2018 21:14:32 +0100 Subject: batman-adv: Fix skbuff rcsum on packet reroute commit fc04fdb2c8a894283259f5621d31d75610701091 upstream. batadv_check_unicast_ttvn may redirect a packet to itself or another originator. This involves rewriting the ttvn and the destination address in the batadv unicast header. These field were not yet pulled (with skb rcsum update) and thus any change to them also requires a change in the receive checksum. Reported-by: Matthias Schiffer Fixes: a73105b8d4c7 ("batman-adv: improved client announcement mechanism") Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- net/batman-adv/routing.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'net/batman-adv') diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index 5015430a9549..9990d4040f6c 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -687,6 +687,7 @@ out: /** * batadv_reroute_unicast_packet - update the unicast header for re-routing * @bat_priv: the bat priv with all the soft interface information + * @skb: unicast packet to process * @unicast_packet: the unicast header to be updated * @dst_addr: the payload destination * @vid: VLAN identifier @@ -698,7 +699,7 @@ out: * Returns true if the packet header has been updated, false otherwise */ static bool -batadv_reroute_unicast_packet(struct batadv_priv *bat_priv, +batadv_reroute_unicast_packet(struct batadv_priv *bat_priv, struct sk_buff *skb, struct batadv_unicast_packet *unicast_packet, uint8_t *dst_addr, unsigned short vid) { @@ -727,8 +728,10 @@ batadv_reroute_unicast_packet(struct batadv_priv *bat_priv, } /* update the packet header */ + skb_postpull_rcsum(skb, unicast_packet, sizeof(*unicast_packet)); ether_addr_copy(unicast_packet->dest, orig_addr); unicast_packet->ttvn = orig_ttvn; + skb_postpush_rcsum(skb, unicast_packet, sizeof(*unicast_packet)); ret = true; out: @@ -768,7 +771,7 @@ static int batadv_check_unicast_ttvn(struct batadv_priv *bat_priv, * the packet to */ if (batadv_tt_local_client_is_roaming(bat_priv, ethhdr->h_dest, vid)) { - if (batadv_reroute_unicast_packet(bat_priv, unicast_packet, + if (batadv_reroute_unicast_packet(bat_priv, skb, unicast_packet, ethhdr->h_dest, vid)) net_ratelimited_function(batadv_dbg, BATADV_DBG_TT, bat_priv, @@ -814,7 +817,7 @@ static int batadv_check_unicast_ttvn(struct batadv_priv *bat_priv, * destination can possibly be updated and forwarded towards the new * target host */ - if (batadv_reroute_unicast_packet(bat_priv, unicast_packet, + if (batadv_reroute_unicast_packet(bat_priv, skb, unicast_packet, ethhdr->h_dest, vid)) { net_ratelimited_function(batadv_dbg, BATADV_DBG_TT, bat_priv, "Rerouting unicast packet to %pM (dst=%pM): TTVN mismatch old_ttvn=%u new_ttvn=%u\n", @@ -837,12 +840,14 @@ static int batadv_check_unicast_ttvn(struct batadv_priv *bat_priv, if (!primary_if) return 0; + /* update the packet header */ + skb_postpull_rcsum(skb, unicast_packet, sizeof(*unicast_packet)); ether_addr_copy(unicast_packet->dest, primary_if->net_dev->dev_addr); + unicast_packet->ttvn = curr_ttvn; + skb_postpush_rcsum(skb, unicast_packet, sizeof(*unicast_packet)); batadv_hardif_free_ref(primary_if); - unicast_packet->ttvn = curr_ttvn; - return 1; } -- cgit v1.2.3