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authorPatrick McHardy <kaber@trash.net>2006-11-28 20:10:21 -0800
committerDavid S. Miller <davem@sunset.davemloft.net>2006-11-28 20:59:38 -0800
commitaf443b6d90de17f7630621269cf0610d9d772670 (patch)
treebd329577450b1d152813117d47796c65a45b39d4 /net
parent2e47c264a2e6ea24c27b4987607222202818c1f4 (diff)
[NETFILTER]: ipt_REJECT: fix memory corruption
On devices with hard_header_len > LL_MAX_HEADER ip_route_me_harder() reallocates the skb, leading to memory corruption when using the stale tcph pointer to update the checksum. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/netfilter/ipt_REJECT.c16
1 files changed, 9 insertions, 7 deletions
diff --git a/net/ipv4/netfilter/ipt_REJECT.c b/net/ipv4/netfilter/ipt_REJECT.c
index ad0312d0e4f..264763adc39 100644
--- a/net/ipv4/netfilter/ipt_REJECT.c
+++ b/net/ipv4/netfilter/ipt_REJECT.c
@@ -114,6 +114,14 @@ static void send_reset(struct sk_buff *oldskb, int hook)
tcph->window = 0;
tcph->urg_ptr = 0;
+ /* Adjust TCP checksum */
+ tcph->check = 0;
+ tcph->check = tcp_v4_check(tcph, sizeof(struct tcphdr),
+ nskb->nh.iph->saddr,
+ nskb->nh.iph->daddr,
+ csum_partial((char *)tcph,
+ sizeof(struct tcphdr), 0));
+
/* Set DF, id = 0 */
nskb->nh.iph->frag_off = htons(IP_DF);
nskb->nh.iph->id = 0;
@@ -129,14 +137,8 @@ static void send_reset(struct sk_buff *oldskb, int hook)
if (ip_route_me_harder(&nskb, addr_type))
goto free_nskb;
- /* Adjust TCP checksum */
nskb->ip_summed = CHECKSUM_NONE;
- tcph->check = 0;
- tcph->check = tcp_v4_check(tcph, sizeof(struct tcphdr),
- nskb->nh.iph->saddr,
- nskb->nh.iph->daddr,
- csum_partial((char *)tcph,
- sizeof(struct tcphdr), 0));
+
/* Adjust IP TTL */
nskb->nh.iph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);