expression: define .clone for catchall set element

commit 5bd6b4981ce649b5e0ae5ec30b7738ef33ef7c6e upstream.

Otherwise reuse of catchall set element expression in variable triggers
a null-pointer dereference.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

2 files changed, 34 insertions, 2 deletions

diff --git a/src/expression.c b/src/expression.c
index 7390089c..37788b18 100644
--- a/src/expression.c
+++ b/src/expression.c
@@ -1341,9 +1341,8 @@ static void set_elem_expr_destroy(struct expr *expr)
 		stmt_free(stmt);
 }
 
-static void set_elem_expr_clone(struct expr *new, const struct expr *expr)
+static void __set_elem_expr_clone(struct expr *new, const struct expr *expr)
 {
-	new->key = expr_clone(expr->key);
 	new->expiration = expr->expiration;
 	new->timeout = expr->timeout;
 	if (expr->comment)
@@ -1351,6 +1350,12 @@ static void set_elem_expr_clone(struct expr *new, const struct expr *expr)
 	init_list_head(&new->stmt_list);
 }
 
+static void set_elem_expr_clone(struct expr *new, const struct expr *expr)
+{
+	new->key = expr_clone(expr->key);
+	__set_elem_expr_clone(new, expr);
+}
+
 static const struct expr_ops set_elem_expr_ops = {
 	.type		= EXPR_SET_ELEM,
 	.name		= "set element",
@@ -1378,11 +1383,17 @@ static void set_elem_catchall_expr_print(const struct expr *expr,
 	nft_print(octx, "*");
 }
 
+static void set_elem_catchall_expr_clone(struct expr *new, const struct expr *expr)
+{
+	__set_elem_expr_clone(new, expr);
+}
+
 static const struct expr_ops set_elem_catchall_expr_ops = {
 	.type		= EXPR_SET_ELEM_CATCHALL,
 	.name		= "catch-all set element",
 	.print		= set_elem_catchall_expr_print,
 	.json		= set_elem_catchall_expr_json,
+	.clone		= set_elem_catchall_expr_clone,
 };
 
 struct expr *set_elem_catchall_expr_alloc(const struct location *loc)
diff --git a/tests/shell/testcases/maps/0017_map_variable_0 b/tests/shell/testcases/maps/0017_map_variable_0
new file mode 100755
index 00000000..70cea88d
--- /dev/null
+++ b/tests/shell/testcases/maps/0017_map_variable_0
@@ -0,0 +1,21 @@
+#!/bin/bash
+
+set -e
+
+RULESET="define x = {
+        1.1.1.1 : 2,
+        * : 3,
+}
+
+table ip x {
+        map y {
+                typeof ip saddr : mark
+                elements = \$x
+        }
+        map z {
+                typeof ip saddr : mark
+                elements = \$x
+        }
+}"
+
+$NFT -f - <<< "$RULESET"