iptables: use match, target and data copy_to_user helpers
authorWillem de Bruijn <willemb@google.com>
Mon, 2 Jan 2017 22:19:41 +0000 (17:19 -0500)
committerPablo Neira Ayuso <pablo@netfilter.org>
Mon, 9 Jan 2017 16:24:53 +0000 (17:24 +0100)
Convert iptables to copying entries, matches and targets one by one,
using the xt_match_to_user and xt_target_to_user helper functions.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
net/ipv4/netfilter/ip_tables.c

index 91656a1d8fbd5b15b306383fe733751fef10f27c..384b85713e062881d3d2554b0828f08ff28f443d 100644 (file)
@@ -826,10 +826,6 @@ copy_entries_to_user(unsigned int total_size,
                return PTR_ERR(counters);
 
        loc_cpu_entry = private->entries;
-       if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
-               ret = -EFAULT;
-               goto free_counters;
-       }
 
        /* FIXME: use iterator macros --RR */
        /* ... then go back and fix counters and names */
@@ -839,6 +835,10 @@ copy_entries_to_user(unsigned int total_size,
                const struct xt_entry_target *t;
 
                e = (struct ipt_entry *)(loc_cpu_entry + off);
+               if (copy_to_user(userptr + off, e, sizeof(*e))) {
+                       ret = -EFAULT;
+                       goto free_counters;
+               }
                if (copy_to_user(userptr + off
                                 + offsetof(struct ipt_entry, counters),
                                 &counters[num],
@@ -852,23 +852,14 @@ copy_entries_to_user(unsigned int total_size,
                     i += m->u.match_size) {
                        m = (void *)e + i;
 
-                       if (copy_to_user(userptr + off + i
-                                        + offsetof(struct xt_entry_match,
-                                                   u.user.name),
-                                        m->u.kernel.match->name,
-                                        strlen(m->u.kernel.match->name)+1)
-                           != 0) {
+                       if (xt_match_to_user(m, userptr + off + i)) {
                                ret = -EFAULT;
                                goto free_counters;
                        }
                }
 
                t = ipt_get_target_c(e);
-               if (copy_to_user(userptr + off + e->target_offset
-                                + offsetof(struct xt_entry_target,
-                                           u.user.name),
-                                t->u.kernel.target->name,
-                                strlen(t->u.kernel.target->name)+1) != 0) {
+               if (xt_target_to_user(t, userptr + off + e->target_offset)) {
                        ret = -EFAULT;
                        goto free_counters;
                }