From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Wunderlich Subject: [PATCH 2/5] batman-adv: update data pointers after skb_cow() Date: Mon, 19 Mar 2018 17:37:23 +0100 Message-ID: <20180319163726.10921-3-sw@simonwunderlich.de> References: <20180319163726.10921-1-sw@simonwunderlich.de> Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, b.a.t.m.a.n-ZwoEplunGu2X36UT3dwllkB+6BGkLq7r@public.gmane.org To: davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org Return-path: In-Reply-To: <20180319163726.10921-1-sw-2YrNx6rUIHYiY0qSoAWiAoQuADTiUCJX@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: b.a.t.m.a.n-bounces-ZwoEplunGu2X36UT3dwllkB+6BGkLq7r@public.gmane.org Sender: "B.A.T.M.A.N" List-Id: netdev.vger.kernel.org From: Matthias Schiffer 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: 7cdcf6dddc42 ("batman-adv: add UNICAST_4ADDR packet type") Signed-off-by: Matthias Schiffer Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich --- net/batman-adv/routing.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index b6891e8b741c..6a9242658c8d 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -968,14 +968,10 @@ int batadv_recv_unicast_packet(struct sk_buff *skb, struct batadv_orig_node *orig_node = NULL, *orig_node_gw = NULL; int check, hdr_size = sizeof(*unicast_packet); enum batadv_subtype subtype; - struct ethhdr *ethhdr; int ret = NET_RX_DROP; bool is4addr, is_gw; unicast_packet = (struct batadv_unicast_packet *)skb->data; - unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; - ethhdr = eth_hdr(skb); - is4addr = unicast_packet->packet_type == BATADV_UNICAST_4ADDR; /* the caller function should have already pulled 2 bytes */ if (is4addr) @@ -995,12 +991,14 @@ int batadv_recv_unicast_packet(struct sk_buff *skb, if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size)) goto free_skb; + unicast_packet = (struct batadv_unicast_packet *)skb->data; + /* packet for me */ if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) { /* If this is a unicast packet from another backgone gw, * drop it. */ - orig_addr_gw = ethhdr->h_source; + orig_addr_gw = eth_hdr(skb)->h_source; orig_node_gw = batadv_orig_hash_find(bat_priv, orig_addr_gw); if (orig_node_gw) { is_gw = batadv_bla_is_backbone_gw(skb, orig_node_gw, @@ -1015,6 +1013,8 @@ int batadv_recv_unicast_packet(struct sk_buff *skb, } if (is4addr) { + unicast_4addr_packet = + (struct batadv_unicast_4addr_packet *)skb->data; subtype = unicast_4addr_packet->subtype; batadv_dat_inc_counter(bat_priv, subtype); -- 2.11.0