sch_sfq: add sanity check for the packet length
The packet length should be checked before the packet data is dereferenced.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index c657628..e85352b 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -122,7 +122,11 @@
switch (skb->protocol) {
case htons(ETH_P_IP):
{
- const struct iphdr *iph = ip_hdr(skb);
+ const struct iphdr *iph;
+
+ if (!pskb_network_may_pull(skb, sizeof(*iph)))
+ goto err;
+ iph = ip_hdr(skb);
h = (__force u32)iph->daddr;
h2 = (__force u32)iph->saddr ^ iph->protocol;
if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) &&
@@ -131,25 +135,32 @@
iph->protocol == IPPROTO_UDPLITE ||
iph->protocol == IPPROTO_SCTP ||
iph->protocol == IPPROTO_DCCP ||
- iph->protocol == IPPROTO_ESP))
+ iph->protocol == IPPROTO_ESP) &&
+ pskb_network_may_pull(skb, iph->ihl * 4 + 4))
h2 ^= *(((u32*)iph) + iph->ihl);
break;
}
case htons(ETH_P_IPV6):
{
- struct ipv6hdr *iph = ipv6_hdr(skb);
+ struct ipv6hdr *iph;
+
+ if (!pskb_network_may_pull(skb, sizeof(*iph)))
+ goto err;
+ iph = ipv6_hdr(skb);
h = (__force u32)iph->daddr.s6_addr32[3];
h2 = (__force u32)iph->saddr.s6_addr32[3] ^ iph->nexthdr;
- if (iph->nexthdr == IPPROTO_TCP ||
- iph->nexthdr == IPPROTO_UDP ||
- iph->nexthdr == IPPROTO_UDPLITE ||
- iph->nexthdr == IPPROTO_SCTP ||
- iph->nexthdr == IPPROTO_DCCP ||
- iph->nexthdr == IPPROTO_ESP)
+ if ((iph->nexthdr == IPPROTO_TCP ||
+ iph->nexthdr == IPPROTO_UDP ||
+ iph->nexthdr == IPPROTO_UDPLITE ||
+ iph->nexthdr == IPPROTO_SCTP ||
+ iph->nexthdr == IPPROTO_DCCP ||
+ iph->nexthdr == IPPROTO_ESP) &&
+ pskb_network_may_pull(skb, sizeof(*iph) + 4))
h2 ^= *(u32*)&iph[1];
break;
}
default:
+err:
h = (unsigned long)skb_dst(skb) ^ (__force u32)skb->protocol;
h2 = (unsigned long)skb->sk;
}