1 files changed, 10 insertions, 5 deletions

diff --git a/net/ipv4/netfilter/nf_nat_proto_common.c b/net/ipv4/netfilter/nf_nat_proto_common.c
index a124213fb9da..871ab0eb325d 100644
--- a/net/ipv4/netfilter/nf_nat_proto_common.c
+++ b/net/ipv4/netfilter/nf_nat_proto_common.c
@@ -42,6 +42,7 @@ int nf_nat_proto_unique_tuple(struct nf_conntrack_tuple *tuple,
 {
         unsigned int range_size, min, i;
         __be16 *portptr;
+        u_int16_t off;
 
         if (maniptype == IP_NAT_MANIP_SRC)
                 portptr = &tuple->src.u.all;
@@ -72,13 +73,17 @@ int nf_nat_proto_unique_tuple(struct nf_conntrack_tuple *tuple,
                 range_size = ntohs(range->max.all) - min + 1;
         }
 
+        off = *rover;
         if (range->flags & IP_NAT_RANGE_PROTO_RANDOM)
-                *rover = net_random();
+                off = net_random();
 
-        for (i = 0; i < range_size; i++, (*rover)++) {
-                *portptr = htons(min + *rover % range_size);
-                if (!nf_nat_used_tuple(tuple, ct))
-                        return 1;
+        for (i = 0; i < range_size; i++, off++) {
+                *portptr = htons(min + off % range_size);
+                if (nf_nat_used_tuple(tuple, ct))
+                        continue;
+                if (!(range->flags & IP_NAT_RANGE_PROTO_RANDOM))
+                        *rover = off;
+                return 1;
         }
         return 0;
 }