1 files changed, 19 insertions, 28 deletions

diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c
index e9486915eff..83acc1405a1 100644
--- a/net/ipv6/netfilter/ip6t_NPT.c
+++ b/net/ipv6/netfilter/ip6t_NPT.c
@@ -9,47 +9,38 @@
 #include <linux/module.h>
 #include <linux/skbuff.h>
 #include <linux/ipv6.h>
+#include <net/ipv6.h>
 #include <linux/netfilter.h>
 #include <linux/netfilter_ipv6.h>
 #include <linux/netfilter_ipv6/ip6t_NPT.h>
 #include <linux/netfilter/x_tables.h>
 
-static __sum16 csum16_complement(__sum16 a)
-{
-	return (__force __sum16)(0xffff - (__force u16)a);
-}
-
-static __sum16 csum16_add(__sum16 a, __sum16 b)
-{
-	u16 sum;
-
-	sum = (__force u16)a + (__force u16)b;
-	sum += (__force u16)a < (__force u16)b;
-	return (__force __sum16)sum;
-}
-
-static __sum16 csum16_sub(__sum16 a, __sum16 b)
-{
-	return csum16_add(a, csum16_complement(b));
-}
-
 static int ip6t_npt_checkentry(const struct xt_tgchk_param *par)
 {
 	struct ip6t_npt_tginfo *npt = par->targinfo;
-	__sum16 src_sum = 0, dst_sum = 0;
+	__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 = csum16_add(src_sum,
-				(__force __sum16)npt->src_pfx.in6.s6_addr16[i]);
-		dst_sum = csum16_add(dst_sum,
-				(__force __sum16)npt->dst_pfx.in6.s6_addr16[i]);
+		src_sum = csum_add(src_sum,
+				(__force __wsum)npt->src_pfx.in6.s6_addr16[i]);
+		dst_sum = csum_add(dst_sum,
+				(__force __wsum)npt->dst_pfx.in6.s6_addr16[i]);
 	}
 
-	npt->adjustment = csum16_sub(src_sum, dst_sum);
+	npt->adjustment = ~csum_fold(csum_sub(src_sum, dst_sum));
 	return 0;
 }
 
@@ -70,7 +61,7 @@ static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt,
 
 		idx = i / 32;
 		addr->s6_addr32[idx] &= mask;
-		addr->s6_addr32[idx] |= npt->dst_pfx.in6.s6_addr32[idx];
+		addr->s6_addr32[idx] |= ~mask & npt->dst_pfx.in6.s6_addr32[idx];
 	}
 
 	if (pfx_len <= 48)
@@ -85,8 +76,8 @@ static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt,
 			return false;
 	}
 
-	sum = csum16_add((__force __sum16)addr->s6_addr16[idx],
-			 npt->adjustment);
+	sum = ~csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
+				  csum_unfold(npt->adjustment)));
 	if (sum == CSUM_MANGLED_0)
 		sum = 0;
 	*(__force __sum16 *)&addr->s6_addr16[idx] = sum;