netfilter: ipset: Fix serious failure in CIDR tracking

[platform/upstream/kernel-adaptation-pc.git] / net / netfilter / ipset / ip_set_hash_gen.h

diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h
index 57beb17..707bc52 100644 (file)
--- a/net/netfilter/ipset/ip_set_hash_gen.h
+++ b/net/netfilter/ipset/ip_set_hash_gen.h
@@ -325,18 +325,22 @@ mtype_add_cidr(struct htype *h, u8 cidr, u8 nets_length)
 static void
 mtype_del_cidr(struct htype *h, u8 cidr, u8 nets_length)
 {
-       u8 i, j;
-
-       for (i = 0; i < nets_length - 1 && h->nets[i].cidr != cidr; i++)
-               ;
-       h->nets[i].nets--;
-
-       if (h->nets[i].nets != 0)
-               return;
-
-       for (j = i; j < nets_length - 1 && h->nets[j].nets; j++) {
-               h->nets[j].cidr = h->nets[j + 1].cidr;
-               h->nets[j].nets = h->nets[j + 1].nets;
+       u8 i, j, net_end = nets_length - 1;
+
+       for (i = 0; i < nets_length; i++) {
+               if (h->nets[i].cidr != cidr)
+                       continue;
+                if (h->nets[i].nets > 1 || i == net_end ||
+                    h->nets[i + 1].nets == 0) {
+                        h->nets[i].nets--;
+                        return;
+                }
+                for (j = i; j < net_end && h->nets[j].nets; j++) {
+                       h->nets[j].cidr = h->nets[j + 1].cidr;
+                       h->nets[j].nets = h->nets[j + 1].nets;
+                }
+                h->nets[j].nets = 0;
+                return;
        }
 }
 #endif