From 897dc80b951e996ba4d26c0038e81a505b92aec1 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 28 Jul 2011 04:00:35 +0000 Subject: [PATCH] ipv6: avoid a dst_entry refcount change in ipv6_destopt_rcv() ipv6_destopt_rcv() runs with rcu_read_lock(), so there is no need to take a temporay reference on dst_entry, even if skb is freed by ip6_parse_tlv() Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv6/exthdrs.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index 79a485e8a700..1318de4c3e8d 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -273,12 +273,12 @@ static int ipv6_destopt_rcv(struct sk_buff *skb) #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) __u16 dstbuf; #endif - struct dst_entry *dst; + struct dst_entry *dst = skb_dst(skb); if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || !pskb_may_pull(skb, (skb_transport_offset(skb) + ((skb_transport_header(skb)[1] + 1) << 3)))) { - IP6_INC_STATS_BH(dev_net(skb_dst(skb)->dev), ip6_dst_idev(skb_dst(skb)), + IP6_INC_STATS_BH(dev_net(dst->dev), ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS); kfree_skb(skb); return -1; @@ -289,9 +289,7 @@ static int ipv6_destopt_rcv(struct sk_buff *skb) dstbuf = opt->dst1; #endif - dst = dst_clone(skb_dst(skb)); if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) { - dst_release(dst); skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3; opt = IP6CB(skb); #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) @@ -304,7 +302,6 @@ static int ipv6_destopt_rcv(struct sk_buff *skb) IP6_INC_STATS_BH(dev_net(dst->dev), ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS); - dst_release(dst); return -1; } -- 2.20.1