netfilter: nf_conntrack_extend: use krealloc() in nf_conntrack_extend.c V2

The ksize() API is going away because it is being abused and it doesn't even
work consistenly across different allocators. Therefore, convert
net/netfilter/nf_conntrack_extend.c to use krealloc().
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/netfilter/nf_conntrack_extend.c

@@ -88,13 +88,11 @@ void *__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
 	newlen = newoff + t->len;
 	rcu_read_unlock();
 
-	if (newlen >= ksize(ct->ext)) {
-		new = kmalloc(newlen, gfp);
-		if (!new)
-			return NULL;
-
-		memcpy(new, ct->ext, ct->ext->len);
+	new = krealloc(ct->ext, newlen, gfp);
+	if (!new)
+		return NULL;
 
+	if (new != ct->ext) {
 		for (i = 0; i < NF_CT_EXT_NUM; i++) {
 			if (!nf_ct_ext_exist(ct, i))
 				continue;