From patchwork Sat Feb 9 12:04:00 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [5/5] netfilter: ip6t_NPT: Ensure to check lower part of prefixes are zero Date: Sat, 09 Feb 2013 02:04:00 -0000 From: Pablo Neira X-Patchwork-Id: 219394 Message-Id: <1360411440-6526-6-git-send-email-pablo@netfilter.org> To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org From: YOSHIFUJI Hideaki / 吉藤英明 RFC 6296 points that address bits that are not part of the prefix has to be zeroed. Signed-off-by: YOSHIFUJI Hideaki Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter/ip6t_NPT.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c index 87b759c..83acc14 100644 --- a/net/ipv6/netfilter/ip6t_NPT.c +++ b/net/ipv6/netfilter/ip6t_NPT.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -18,11 +19,20 @@ static int ip6t_npt_checkentry(const struct xt_tgchk_param *par) { struct ip6t_npt_tginfo *npt = par->targinfo; __wsum src_sum = 0, dst_sum = 0; + struct in6_addr pfx; unsigned int i; if (npt->src_pfx_len > 64 || npt->dst_pfx_len > 64) return -EINVAL; + /* Ensure that LSB of prefix is zero */ + ipv6_addr_prefix(&pfx, &npt->src_pfx.in6, npt->src_pfx_len); + if (!ipv6_addr_equal(&pfx, &npt->src_pfx.in6)) + return -EINVAL; + ipv6_addr_prefix(&pfx, &npt->dst_pfx.in6, npt->dst_pfx_len); + if (!ipv6_addr_equal(&pfx, &npt->dst_pfx.in6)) + return -EINVAL; + for (i = 0; i < ARRAY_SIZE(npt->src_pfx.in6.s6_addr16); i++) { src_sum = csum_add(src_sum, (__force __wsum)npt->src_pfx.in6.s6_addr16[i]);