parser_json: fix handle memleak from error path

Based on patch from Sebastian Walz.

Fixes: 586ad210368b ("libnftables: Implement JSON parser")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/src/parser_json.c b/src/parser_json.c
index 8ca44efbb52ec5710df398fdfa4d0eb94cde724b..d18188d81b3f21c1b858feb1509ddc07e8e10e09 100644 (file)
--- a/src/parser_json.c
+++ b/src/parser_json.c
@@ -3168,8 +3168,7 @@ static struct cmd *json_parse_cmd_add_chain(struct json_ctx *ctx, json_t *root,
        chain->hook.name = chain_hookname_lookup(hookstr);
        if (!chain->hook.name) {
                json_error(ctx, "Invalid chain hook '%s'.", hookstr);
-               chain_free(chain);
-               return NULL;
+               goto err_free_chain;
        }
 
        json_unpack(root, "{s:o}", "dev", &devs);
@@ -3178,8 +3177,7 @@ static struct cmd *json_parse_cmd_add_chain(struct json_ctx *ctx, json_t *root,
                chain->dev_expr = json_parse_devs(ctx, devs);
                if (!chain->dev_expr) {
                        json_error(ctx, "Invalid chain dev.");
-                       chain_free(chain);
-                       return NULL;
+                       goto err_free_chain;
                }
        }
 
@@ -3187,8 +3185,7 @@ static struct cmd *json_parse_cmd_add_chain(struct json_ctx *ctx, json_t *root,
                chain->policy = parse_policy(policy);
                if (!chain->policy) {
                        json_error(ctx, "Unknown policy '%s'.", policy);
-                       chain_free(chain);
-                       return NULL;
+                       goto err_free_chain;
                }
        }
 
@@ -3197,6 +3194,11 @@ static struct cmd *json_parse_cmd_add_chain(struct json_ctx *ctx, json_t *root,
 
        handle_merge(&chain->handle, &h);
        return cmd_alloc(op, obj, &h, int_loc, chain);
+
+err_free_chain:
+       chain_free(chain);
+       handle_free(&h);
+       return NULL;
 }
 
 static struct cmd *json_parse_cmd_add_rule(struct json_ctx *ctx, json_t *root,
@@ -3236,6 +3238,7 @@ static struct cmd *json_parse_cmd_add_rule(struct json_ctx *ctx, json_t *root,
 
        if (!json_is_array(tmp)) {
                json_error(ctx, "Value of property \"expr\" must be an array.");
+               handle_free(&h);
                return NULL;
        }
 
@@ -3255,16 +3258,14 @@ static struct cmd *json_parse_cmd_add_rule(struct json_ctx *ctx, json_t *root,
                if (!json_is_object(value)) {
                        json_error(ctx, "Unexpected expr array element of type %s, expected object.",
                                   json_typename(value));
-                       rule_free(rule);
-                       return NULL;
+                       goto err_free_rule;
                }
 
                stmt = json_parse_stmt(ctx, value);
 
                if (!stmt) {
                        json_error(ctx, "Parsing expr array at index %zd failed.", index);
-                       rule_free(rule);
-                       return NULL;
+                       goto err_free_rule;
                }
 
                rule_stmt_append(rule, stmt);
@@ -3274,6 +3275,11 @@ static struct cmd *json_parse_cmd_add_rule(struct json_ctx *ctx, json_t *root,
                json_object_del(root, "handle");
 
        return cmd_alloc(op, obj, &h, int_loc, rule);
+
+err_free_rule:
+       rule_free(rule);
+       handle_free(&h);
+       return NULL;
 }
 
 static int string_to_nft_object(const char *str)
@@ -3654,8 +3660,7 @@ static struct cmd *json_parse_cmd_add_object(struct json_ctx *ctx,
                        if (ret < 0 || ret >= (int)sizeof(obj->secmark.ctx)) {
                                json_error(ctx, "Invalid secmark context '%s', max length is %zu.",
                                           tmp, sizeof(obj->secmark.ctx));
-                               obj_free(obj);
-                               return NULL;
+                               goto err_free_obj;
                        }
                }
                break;
@@ -3671,8 +3676,7 @@ static struct cmd *json_parse_cmd_add_object(struct json_ctx *ctx,
                            ret >= (int)sizeof(obj->ct_helper.name)) {
                                json_error(ctx, "Invalid CT helper type '%s', max length is %zu.",
                                           tmp, sizeof(obj->ct_helper.name));
-                               obj_free(obj);
-                               return NULL;
+                               goto err_free_obj;
                        }
                }
                if (!json_unpack(root, "{s:s}", "protocol", &tmp)) {
@@ -3682,15 +3686,13 @@ static struct cmd *json_parse_cmd_add_object(struct json_ctx *ctx,
                                obj->ct_helper.l4proto = IPPROTO_UDP;
                        } else {
                                json_error(ctx, "Invalid ct helper protocol '%s'.", tmp);
-                               obj_free(obj);
-                               return NULL;
+                               goto err_free_obj;
                        }
                }
                if (!json_unpack(root, "{s:s}", "l3proto", &tmp) &&
                    parse_family(tmp, &l3proto)) {
                        json_error(ctx, "Invalid ct helper l3proto '%s'.", tmp);
-                       obj_free(obj);
-                       return NULL;
+                       goto err_free_obj;
                }
                obj->ct_helper.l3proto = l3proto;
                break;
@@ -3704,23 +3706,19 @@ static struct cmd *json_parse_cmd_add_object(struct json_ctx *ctx,
                                obj->ct_timeout.l4proto = IPPROTO_UDP;
                        } else {
                                json_error(ctx, "Invalid ct timeout protocol '%s'.", tmp);
-                               obj_free(obj);
-                               return NULL;
+                               goto err_free_obj;
                        }
                }
                if (!json_unpack(root, "{s:s}", "l3proto", &tmp) &&
                    parse_family(tmp, &l3proto)) {
                        json_error(ctx, "Invalid ct timeout l3proto '%s'.", tmp);
-                       obj_free(obj);
-                       return NULL;
+                       goto err_free_obj;
                }
                obj->ct_timeout.l3proto = l3proto;
 
                init_list_head(&obj->ct_timeout.timeout_list);
-               if (json_parse_ct_timeout_policy(ctx, root, obj)) {
-                       obj_free(obj);
-                       return NULL;
-               }
+               if (json_parse_ct_timeout_policy(ctx, root, obj))
+                       goto err_free_obj;
                break;
        case NFT_OBJECT_CT_EXPECT:
                cmd_obj = CMD_OBJ_CT_EXPECT;
@@ -3728,8 +3726,7 @@ static struct cmd *json_parse_cmd_add_object(struct json_ctx *ctx,
                if (!json_unpack(root, "{s:s}", "l3proto", &tmp) &&
                    parse_family(tmp, &l3proto)) {
                        json_error(ctx, "Invalid ct expectation l3proto '%s'.", tmp);
-                       obj_free(obj);
-                       return NULL;
+                       goto err_free_obj;
                }
                obj->ct_expect.l3proto = l3proto;
                if (!json_unpack(root, "{s:s}", "protocol", &tmp)) {
@@ -3739,8 +3736,7 @@ static struct cmd *json_parse_cmd_add_object(struct json_ctx *ctx,
                                obj->ct_expect.l4proto = IPPROTO_UDP;
                        } else {
                                json_error(ctx, "Invalid ct expectation protocol '%s'.", tmp);
-                               obj_free(obj);
-                               return NULL;
+                               goto err_free_obj;
                        }
                }
                if (!json_unpack(root, "{s:i}", "dport", &i))
@@ -3754,10 +3750,9 @@ static struct cmd *json_parse_cmd_add_object(struct json_ctx *ctx,
                obj->type = NFT_OBJECT_LIMIT;
                if (json_unpack_err(ctx, root, "{s:I, s:s}",
                                    "rate", &obj->limit.rate,
-                                   "per", &tmp)) {
-                       obj_free(obj);
-                       return NULL;
-               }
+                                   "per", &tmp))
+                       goto err_free_obj;
+
                json_unpack(root, "{s:s}", "rate_unit", &rate_unit);
                json_unpack(root, "{s:b}", "inv", &inv);
                json_unpack(root, "{s:i}", "burst", &obj->limit.burst);
@@ -3778,20 +3773,18 @@ static struct cmd *json_parse_cmd_add_object(struct json_ctx *ctx,
        case CMD_OBJ_SYNPROXY:
                obj->type = NFT_OBJECT_SYNPROXY;
                if (json_unpack_err(ctx, root, "{s:i, s:i}",
-                                   "mss", &i, "wscale", &j)) {
-                       obj_free(obj);
-                       return NULL;
-               }
+                                   "mss", &i, "wscale", &j))
+                       goto err_free_obj;
+
                obj->synproxy.mss = i;
                obj->synproxy.wscale = j;
                obj->synproxy.flags |= NF_SYNPROXY_OPT_MSS;
                obj->synproxy.flags |= NF_SYNPROXY_OPT_WSCALE;
                if (!json_unpack(root, "{s:o}", "flags", &jflags)) {
                        flags = json_parse_synproxy_flags(ctx, jflags);
-                       if (flags < 0) {
-                               obj_free(obj);
-                               return NULL;
-                       }
+                       if (flags < 0)
+                               goto err_free_obj;
+
                        obj->synproxy.flags |= flags;
                }
                break;
@@ -3803,6 +3796,11 @@ static struct cmd *json_parse_cmd_add_object(struct json_ctx *ctx,
                json_object_del(root, "handle");
 
        return cmd_alloc(op, cmd_obj, &h, int_loc, obj);
+
+err_free_obj:
+       obj_free(obj);
+       handle_free(&h);
+       return NULL;
 }
 
 static struct cmd *json_parse_cmd_add(struct json_ctx *ctx,
@@ -3917,8 +3915,7 @@ static struct cmd *json_parse_cmd_replace(struct json_ctx *ctx,
                if (!json_is_object(value)) {
                        json_error(ctx, "Unexpected expr array element of type %s, expected object.",
                                   json_typename(value));
-                       rule_free(rule);
-                       return NULL;
+                       goto err_free_replace;
                }
 
                stmt = json_parse_stmt(ctx, value);
@@ -3926,8 +3923,7 @@ static struct cmd *json_parse_cmd_replace(struct json_ctx *ctx,
                if (!stmt) {
                        json_error(ctx, "Parsing expr array at index %zd failed.",
                                   index);
-                       rule_free(rule);
-                       return NULL;
+                       goto err_free_replace;
                }
 
                rule_stmt_append(rule, stmt);
@@ -3937,6 +3933,11 @@ static struct cmd *json_parse_cmd_replace(struct json_ctx *ctx,
                json_object_del(root, "handle");
 
        return cmd_alloc(op, CMD_OBJ_RULE, &h, int_loc, rule);
+
+err_free_replace:
+       rule_free(rule);
+       handle_free(&h);
+       return NULL;
 }
 
 static struct cmd *json_parse_cmd_list_multiple(struct json_ctx *ctx,