Alex Chen <alex.c...@huawei.com> writes:
> In qobject_type(), NULL is returned when the 'QObject' returned from
> parse_value() is not of QString type,
> and this 'QObject' memory will leaked.
> So we need to first check whether the 'QObject' returned from parse_value()
> is of QString type,
> and if not, we free 'QObject' memory and return an error.
>
> The memleak stack is as follows:
> Direct leak of 32 byte(s) in 1 object(s) allocated from:
> #0 0xfffe4b3c34fb in __interceptor_malloc (/lib64/libasan.so.4+0xd34fb)
> #1 0xfffe4ae48aa3 in g_malloc (/lib64/libglib-2.0.so.0+0x58aa3)
> #2 0xaaab3557d9f7 in qnum_from_int
> /Images/source_org/qemu_master/qemu/qobject/qnum.c:25
> #3 0xaaab35584d23 in parse_literal
> /Images/source_org/qemu_master/qemu/qobject/json-parser.c:511
> #4 0xaaab35584d23 in parse_value
> /Images/source_org/qemu_master/qemu/qobject/json-parser.c:554
> #5 0xaaab35583d77 in parse_pair
> /Images/source_org/qemu_master/qemu/qobject/json-parser.c:270
> #6 0xaaab355845db in parse_object
> /Images/source_org/qemu_master/qemu/qobject/json-parser.c:327
> #7 0xaaab355845db in parse_value
> /Images/source_org/qemu_master/qemu/qobject/json-parser.c:546
> #8 0xaaab35585b1b in json_parser_parse
> /Images/source_org/qemu_master/qemu/qobject/json-parser.c:580
> #9 0xaaab35583703 in json_message_process_token
> /Images/source_org/qemu_master/qemu/qobject/json-streamer.c:92
> #10 0xaaab355ddccf in json_lexer_feed_char
> /Images/source_org/qemu_master/qemu/qobject/json-lexer.c:313
> #11 0xaaab355de0eb in json_lexer_feed
> /Images/source_org/qemu_master/qemu/qobject/json-lexer.c:350
> #12 0xaaab354aff67 in tcp_chr_read
> /Images/source_org/qemu_master/qemu/chardev/char-socket.c:525
> #13 0xfffe4ae429db in g_main_context_dispatch
> (/lib64/libglib-2.0.so.0+0x529db)
> #14 0xfffe4ae42d8f (/lib64/libglib-2.0.so.0+0x52d8f)
> #15 0xfffe4ae430df in g_main_loop_run (/lib64/libglib-2.0.so.0+0x530df)
> #16 0xaaab34d70bff in iothread_run
> /Images/source_org/qemu_master/qemu/iothread.c:82
> #17 0xaaab3559d71b in qemu_thread_start
> /Images/source_org/qemu_master/qemu/util/qemu-thread-posix.c:519
Good catch, thanks!
> Fixes: 532fb5328473 ("qapi: Make more of qobject_to()")
> Reported-by: Euler Robot <euler.ro...@huawei.com>
> Signed-off-by: Alex Chen <alex.c...@huawei.com>
> Signed-off-by: Chen Qun <kuhn.chen...@huawei.com>
> ---
> qobject/json-parser.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/qobject/json-parser.c b/qobject/json-parser.c
> index d083810d37..b37762a203 100644
> --- a/qobject/json-parser.c
> +++ b/qobject/json-parser.c
> @@ -267,10 +267,13 @@ static int parse_pair(JSONParserContext *ctxt, QDict
> *dict)
> goto out;
> }
>
> - key = qobject_to(QString, parse_value(ctxt));
> - if (!key) {
> - parse_error(ctxt, peek, "key is not a string in object");
> + value = parse_value(ctxt);
> + if (!value || qobject_type(value) != QTYPE_QSTRING) {
The "is string" test becomes more cumbersome. Also, we reuse @value for
another purpose.
> + qobject_unref(value);
> + parse_error(ctxt, peek, "value is not a string in object");
Changing error messages in a memory leak fix is inappropriate.
Accident?
> goto out;
> + } else {
> + key = qobject_to(QString, value);
> }
>
> token = parser_context_pop_token(ctxt);
Here's a simpler, straightforward fix, with a test case thrown in:
diff --git a/qobject/json-parser.c b/qobject/json-parser.c
index d083810d37..c0f521b56b 100644
--- a/qobject/json-parser.c
+++ b/qobject/json-parser.c
@@ -257,8 +257,9 @@ static JSONToken
*parser_context_peek_token(JSONParserContext *ctxt)
*/
static int parse_pair(JSONParserContext *ctxt, QDict *dict)
{
+ QObject *key_obj = NULL;
+ QString *key;
QObject *value;
- QString *key = NULL;
JSONToken *peek, *token;
peek = parser_context_peek_token(ctxt);
@@ -267,7 +268,8 @@ static int parse_pair(JSONParserContext *ctxt, QDict *dict)
goto out;
}
- key = qobject_to(QString, parse_value(ctxt));
+ key_obj = parse_value(ctxt);
+ key = qobject_to(QString, key_obj);
if (!key) {
parse_error(ctxt, peek, "key is not a string in object");
goto out;
@@ -297,13 +299,11 @@ static int parse_pair(JSONParserContext *ctxt, QDict
*dict)
qdict_put_obj(dict, qstring_get_str(key), value);
- qobject_unref(key);
-
+ qobject_unref(key_obj);
return 0;
out:
- qobject_unref(key);
-
+ qobject_unref(key_obj);
return -1;
}
diff --git a/tests/check-qjson.c b/tests/check-qjson.c
index 07a773e653..9a02079099 100644
--- a/tests/check-qjson.c
+++ b/tests/check-qjson.c
@@ -1415,6 +1415,14 @@ static void invalid_dict_comma(void)
g_assert(obj == NULL);
}
+static void invalid_dict_key(void)
+{
+ Error *err = NULL;
+ QObject *obj = qobject_from_json("{32:'abc'}", &err);
+ error_free_or_abort(&err);
+ g_assert(obj == NULL);
+}
+
static void unterminated_literal(void)
{
Error *err = NULL;
@@ -1500,6 +1508,7 @@ int main(int argc, char **argv)
g_test_add_func("/errors/unterminated/dict_comma",
unterminated_dict_comma);
g_test_add_func("/errors/invalid_array_comma", invalid_array_comma);
g_test_add_func("/errors/invalid_dict_comma", invalid_dict_comma);
+ g_test_add_func("/errors/invalid_dict_key", invalid_dict_key);
g_test_add_func("/errors/unterminated/literal", unterminated_literal);
g_test_add_func("/errors/limits/nesting", limits_nesting);
g_test_add_func("/errors/multiple_values", multiple_values);
