From patchwork Sat Jan 26 18:38:23 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [RFC, 3/4] netfilter ip6t_NPT: Ensure to check lower part of prefixes are zero. Date: Sat, 26 Jan 2013 08:38:23 -0000 From: =?utf-8?b?WU9TSElGVUpJIEhpZGVha2kgLyDlkInol6Toi7HmmI4=?= X-Patchwork-Id: 215924 Message-Id: <5104229F.9000501@linux-ipv6.org> To: netfilter-devel@vger.kernel.org Cc: jm@dilly.me, fw@strlen.de, yoshfuji@linux-ipv6.org Signed-off-by: YOSHIFUJI Hideaki --- 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 b1bf3ed..7d23d22 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 @@ -18,10 +19,19 @@ static int ip6t_npt_checkentry(const struct xt_tgchk_param *par) { struct ip6t_npt_tginfo *npt = par->targinfo; __wsum src_sum, dst_sum; + struct in6_addr pfx; 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; + src_sum = csum_partial(&npt->src_pfx.in6, sizeof(npt->src_pfx.in6), 0); dst_sum = csum_partial(&npt->dst_pfx.in6, sizeof(npt->dst_pfx.in6), 0);