json: Fix memleaks in echo support

When extracting netlink message data for populating JSON objects with
handles, allocated nftnl objects were not freed. Though since freeing
these objects also frees retrieved string attributes, copy them using
strdupa() which takes care of memory deallocation upon function return.
This is ideal since these strings are used only to find the right JSON
object to insert the handle into.

Fixes: bb32d8db9a125 ("JSON: Add support for echo option")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/src/parser_json.c b/src/parser_json.c
index 6755d39c34f0adcbf56771bdc629444e069a8c10..c92113ba516c27aae6c64a12340209b7018d25e5 100644 (file)
--- a/src/parser_json.c
+++ b/src/parser_json.c
@@ -1,3 +1,4 @@
+#define _GNU_SOURCE
 #include <errno.h>
 #include <stdint.h> /* needed by gmputil.h */
 #include <string.h>
@@ -3485,8 +3486,9 @@ static int json_update_table(struct netlink_mon_handler *monh,
 
        nlt = netlink_table_alloc(nlh);
        family = family2str(nftnl_table_get_u32(nlt, NFTNL_TABLE_FAMILY));
-       name = nftnl_table_get_str(nlt, NFTNL_TABLE_NAME);
+       name = strdupa(nftnl_table_get_str(nlt, NFTNL_TABLE_NAME));
        handle = nftnl_table_get_u64(nlt, NFTNL_TABLE_HANDLE);
+       nftnl_table_free(nlt);
 
        json_array_foreach(array, index, value) {
                if (json_unpack(value, "{s:{s:o}}", "add", "table", &value) ||
@@ -3512,9 +3514,10 @@ static int json_update_chain(struct netlink_mon_handler *monh,
 
        nlc = netlink_chain_alloc(nlh);
        family = family2str(nftnl_chain_get_u32(nlc, NFTNL_CHAIN_FAMILY));
-       table = nftnl_chain_get_str(nlc, NFTNL_CHAIN_TABLE);
-       name = nftnl_chain_get_str(nlc, NFTNL_CHAIN_NAME);
+       table = strdupa(nftnl_chain_get_str(nlc, NFTNL_CHAIN_TABLE));
+       name = strdupa(nftnl_chain_get_str(nlc, NFTNL_CHAIN_NAME));
        handle = nftnl_chain_get_u64(nlc, NFTNL_CHAIN_HANDLE);
+       nftnl_chain_free(nlc);
 
        json_array_foreach(array, index, value) {
                if (json_unpack(value, "{s:{s:o}}", "add", "chain", &value) ||
@@ -3540,9 +3543,10 @@ static int json_update_rule(struct netlink_mon_handler *monh,
 
        nlr = netlink_rule_alloc(nlh);
        family = family2str(nftnl_rule_get_u32(nlr, NFTNL_RULE_FAMILY));
-       table = nftnl_rule_get_str(nlr, NFTNL_RULE_TABLE);
-       chain = nftnl_rule_get_str(nlr, NFTNL_RULE_CHAIN);
+       table = strdupa(nftnl_rule_get_str(nlr, NFTNL_RULE_TABLE));
+       chain = strdupa(nftnl_rule_get_str(nlr, NFTNL_RULE_CHAIN));
        handle = nftnl_rule_get_u64(nlr, NFTNL_RULE_HANDLE);
+       nftnl_rule_free(nlr);
 
        json_array_foreach(array, index, value) {
                if (json_unpack(value, "{s:{s:o}}", "add", "rule", &value) ||
@@ -3574,13 +3578,16 @@ static int json_update_set(struct netlink_mon_handler *monh,
 
        nls = netlink_set_alloc(nlh);
        flags = nftnl_set_get_u32(nls, NFTNL_SET_FLAGS);
-       if (flags & NFT_SET_ANONYMOUS)
+       if (flags & NFT_SET_ANONYMOUS) {
+               nftnl_set_free(nls);
                return MNL_CB_OK;
+       }
 
        family = family2str(nftnl_set_get_u32(nls, NFTNL_SET_FAMILY));
-       table = nftnl_set_get_str(nls, NFTNL_SET_TABLE);
-       name = nftnl_set_get_str(nls, NFTNL_SET_NAME);
+       table = strdupa(nftnl_set_get_str(nls, NFTNL_SET_TABLE));
+       name = strdupa(nftnl_set_get_str(nls, NFTNL_SET_NAME));
        handle = nftnl_set_get_u64(nls, NFTNL_SET_HANDLE);
+       nftnl_set_free(nls);
 
        json_array_foreach(array, index, value) {
                if (json_unpack(value, "{s:{s:o}}", "add", "set", &value) ||
@@ -3605,10 +3612,11 @@ static int json_update_obj(struct netlink_mon_handler *monh,
 
        nlo = netlink_obj_alloc(nlh);
        family = family2str(nftnl_obj_get_u32(nlo, NFTNL_OBJ_FAMILY));
-       table = nftnl_obj_get_str(nlo, NFTNL_OBJ_TABLE);
-       name = nftnl_obj_get_str(nlo, NFTNL_OBJ_NAME);
+       table = strdupa(nftnl_obj_get_str(nlo, NFTNL_OBJ_TABLE));
+       name = strdupa(nftnl_obj_get_str(nlo, NFTNL_OBJ_NAME));
        type = obj_type_name(nftnl_obj_get_u32(nlo, NFTNL_OBJ_TYPE));
        handle = nftnl_obj_get_u64(nlo, NFTNL_OBJ_HANDLE);
+       nftnl_obj_free(nlo);
 
        json_array_foreach(array, index, value) {
                if (json_unpack(value, "{s:{s:o}}", "add", type, &value) ||