From 4b1d488a285a446329825d5fe91f987b7880e6e5 Mon Sep 17 00:00:00 2001 From: Yotam Gigi Date: Mon, 26 Sep 2016 13:45:25 +0300 Subject: [PATCH] act_ife: Fix external mac header on encode On ife encode side, external mac header is copied from the original packet and may be overridden if the user requests. Before, the mac header copy was done from memory region that might not be accessible anymore, as skb_cow_head might free it and copy the packet. This led to random values in the external mac header once the values were not set by user. This fix takes the internal mac header from the packet, after the call to skb_cow_head. Fixes: ef6980b6becb ("net sched: introduce IFE action") Acked-by: Jamal Hadi Salim Signed-off-by: Yotam Gigi Signed-off-by: David S. Miller --- net/sched/act_ife.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/sched/act_ife.c b/net/sched/act_ife.c index e87cd81315e1..88ac9a8c9bbd 100644 --- a/net/sched/act_ife.c +++ b/net/sched/act_ife.c @@ -740,8 +740,6 @@ static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a, return TC_ACT_SHOT; } - iethh = eth_hdr(skb); - err = skb_cow_head(skb, hdrm); if (unlikely(err)) { ife->tcf_qstats.drops++; @@ -752,6 +750,7 @@ static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a, if (!(at & AT_EGRESS)) skb_push(skb, skb->dev->hard_header_len); + iethh = (struct ethhdr *)skb->data; __skb_push(skb, hdrm); memcpy(skb->data, iethh, skb->mac_len); skb_reset_mac_header(skb); -- 2.20.1