act_nat: not all of the ICMP packets need an IP header payload
not all of the ICMP packets need an IP header payload, so we check the length
of the skbs only when the packets should have an IP header payload.
Based upon analysis and initial patch by Rodrigo Partearroyo González.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
----
net/sched/act_nat.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/act_nat.c b/net/sched/act_nat.c
index 5709494..724553e 100644
--- a/net/sched/act_nat.c
+++ b/net/sched/act_nat.c
@@ -205,7 +205,7 @@
{
struct icmphdr *icmph;
- if (!pskb_may_pull(skb, ihl + sizeof(*icmph) + sizeof(*iph)))
+ if (!pskb_may_pull(skb, ihl + sizeof(*icmph)))
goto drop;
icmph = (void *)(skb_network_header(skb) + ihl);
@@ -215,6 +215,9 @@
(icmph->type != ICMP_PARAMETERPROB))
break;
+ if (!pskb_may_pull(skb, ihl + sizeof(*icmph) + sizeof(*iph)))
+ goto drop;
+
iph = (void *)(icmph + 1);
if (egress)
addr = iph->daddr;
