[MCAST] IPv6: Check packet size when process Multicast
Signed-off-by: Yan Zheng <yanzheng@21cn.com
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index c4f2a0e..966b237 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1087,7 +1087,7 @@
int igmp6_event_query(struct sk_buff *skb)
{
- struct mld2_query *mlh2 = (struct mld2_query *) skb->h.raw;
+ struct mld2_query *mlh2 = NULL;
struct ifmcaddr6 *ma;
struct in6_addr *group;
unsigned long max_delay;
@@ -1140,6 +1140,13 @@
/* clear deleted report items */
mld_clear_delrec(idev);
} else if (len >= 28) {
+ int srcs_offset = sizeof(struct mld2_query) -
+ sizeof(struct icmp6hdr);
+ if (!pskb_may_pull(skb, srcs_offset)) {
+ in6_dev_put(idev);
+ return -EINVAL;
+ }
+ mlh2 = (struct mld2_query *) skb->h.raw;
max_delay = (MLDV2_MRC(ntohs(mlh2->mrc))*HZ)/1000;
if (!max_delay)
max_delay = 1;
@@ -1156,7 +1163,15 @@
return 0;
}
/* mark sources to include, if group & source-specific */
- mark = mlh2->nsrcs != 0;
+ if (mlh2->nsrcs != 0) {
+ if (!pskb_may_pull(skb, srcs_offset +
+ mlh2->nsrcs * sizeof(struct in6_addr))) {
+ in6_dev_put(idev);
+ return -EINVAL;
+ }
+ mlh2 = (struct mld2_query *) skb->h.raw;
+ mark = 1;
+ }
} else {
in6_dev_put(idev);
return -EINVAL;