Re: [PATCH v2] json: Fix a memleak in parse_pair()

[Markus Armbruster]

Alex Chen <alex.chen@huawei.com> writes:

> On 2020/11/16 19:43, Philippe Mathieu-Daudé wrote:
>> On 11/16/20 7:42 AM, Markus Armbruster wrote:
>>> "Chenqun (kuhn)" <kuhn.chenqun@huawei.com> writes:
>>>
>>>>> -----Original Message-----
>>>>> From: Chenzhendong (alex)
>>>>> Sent: Friday, November 13, 2020 10:55 PM
>>>>> To: armbru@redhat.com
>>>>> Cc: Chenzhendong (alex) <alex.chen@huawei.com>; qemu-devel@nongnu.org;
>>>>> qemu-trivial@nongnu.org; Zhanghailiang <zhang.zhanghailiang@huawei.com>;
>>>>> Chenqun (kuhn) <kuhn.chenqun@huawei.com>
>>>>> Subject: [PATCH v2] json: Fix a memleak in parse_pair()
>>>>>
>>>>> 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 cache the 'QObject' returned from parse_value(), and 
>>>>> finally
>>>>> free 'QObject' memory at the end of the function.
>>>>> Also, we add a testcast about invalid dict key.
>>>>>
>>>>> 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
>>>>>
>> ...
>>>
>>> Queued, thanks!
>> 
>> If possible can you s%/Images/source_org/qemu_master/qemu/%% to make
>> description more readable...?
>> 
>
> Hi Philippe,
> I am sorry for that, considering that the patch has been queued,
> do I need to modify the commit message and send patch v3?

I'll take care of it, no need to respin.  Thanks!