From 389f48947a5a37ea283de520abb742d42174edb0 Mon Sep 17 00:00:00 2001 From: Li RongQing Date: Fri, 17 Oct 2014 14:03:08 +0800 Subject: [PATCH] openvswitch: fix a use after free pskb_may_pull() called by arphdr_ok can change skb->data, so put the arp setting after arphdr_ok to avoid the use the freed memory Fixes: 0714812134d7d ("openvswitch: Eliminate memset() from flow_extract.") Cc: Jesse Gross Cc: Eric Dumazet Signed-off-by: Li RongQing Acked-by: Jesse Gross Signed-off-by: David S. Miller --- net/openvswitch/flow.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c index 62db02ba36bc..c5cfc72a5535 100644 --- a/net/openvswitch/flow.c +++ b/net/openvswitch/flow.c @@ -557,10 +557,11 @@ static int key_extract(struct sk_buff *skb, struct sw_flow_key *key) } else if (key->eth.type == htons(ETH_P_ARP) || key->eth.type == htons(ETH_P_RARP)) { struct arp_eth_header *arp; + bool arp_available = arphdr_ok(skb); arp = (struct arp_eth_header *)skb_network_header(skb); - if (arphdr_ok(skb) && + if (arp_available && arp->ar_hrd == htons(ARPHRD_ETHER) && arp->ar_pro == htons(ETH_P_IP) && arp->ar_hln == ETH_ALEN &&