Re: [PATCH][MCAST]IPv6: Check packet size when process Multicast Address and Source Specific Query
From: Yan Zheng <hidden>
Date: 2005-10-31 12:08:49
Also in:
lkml
You cannot continue using mlh2, local copy of skb->h.raw after pskb_may_pull(). Please refresh it. --yoshfuji
My mistake. sorry. I hope the new one is correct. Regards ================================================================================
--- linux-2.6.14/net/ipv6/mcast.c 2005-10-30 23:09:33.000000000 +0800
+++ linux/net/ipv6/mcast.c 2005-10-31 14:16:19.000000000 +0800@@ -1087,7 +1087,7 @@ static void mld_marksources(struct ifmca 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 @@ int igmp6_event_query(struct sk_buff *sk /* 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 @@ int igmp6_event_query(struct sk_buff *sk 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;