iptables: Reset pointer after freeing

The match or the target might be reused in the next invocation
of iptables and then xtables operates on this invalid pointer.
xt_t->t and xt_m->m are keept alive via the global variables
xtables_targets and xtables_matches.

diff --git a/src/iptables.c b/src/iptables.c
index 4d46a5b..44c5c73 100644 (file)
--- a/src/iptables.c
+++ b/src/iptables.c
@@ -2048,10 +2048,14 @@ static void cleanup_parse_context(struct parse_context *ctx)
 {
        g_strfreev(ctx->argv);
        g_free(ctx->ip);
-       if (ctx->xt_t != NULL)
+       if (ctx->xt_t != NULL) {
                g_free(ctx->xt_t->t);
-       if (ctx->xt_m != NULL)
+               ctx->xt_t->t = NULL;
+       }
+       if (ctx->xt_m != NULL) {
                g_free(ctx->xt_m->m);
+               ctx->xt_m->m = NULL;
+       }
        g_free(ctx);
 }