Re: [PATCH] qom-qmp-cmds: remove unnecessary alloc in qmp_object_add to fix memleak

[Markus Armbruster]

Paolo, looks like this has fallen through the cracks.  If you'd prefer
me to take it, let me know.

Markus Armbruster <address@hidden> writes:

> Pan Nengyuan <address@hidden> writes:
>
>> In qmp_object_add(), user_creatable_add_type() may set errp with some error 
>> message and
>> return NULL. In this case, qmp_object_add() still alloc memory to *ret_data 
>> which return
>> to the caller and causes a memory leak.
>>
>> This patch do this alloc() action only if obj is not NULL to fix it. And 
>> initialize ret_data
>> in xen-block to avoid a possible uninitialized error.
>>
>> The Leak stack:
>> Direct leak of 4120 byte(s) in 1 object(s) allocated from:
>>     #0 0x7f6106ce5970 in __interceptor_calloc (/lib64/libasan.so.5+0xef970)
>>     #1 0x7f6105e6a49d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5249d)
>>     #2 0x55d2c58c17fd in qdict_new 
>> /mnt/sdb/qemu-new/qemu_test/qemu/qobject/qdict.c:29
>>     #3 0x55d2c53a0051 in qmp_object_add 
>> /mnt/sdb/qemu-new/qemu_test/qemu/qom/qom-qmp-cmds.c:291
>>     #4 0x55d2c57b47da in do_qmp_dispatch 
>> /mnt/sdb/qemu-new/qemu_test/qemu/qapi/qmp-dispatch.c:132
>>     #5 0x55d2c57b47da in qmp_dispatch 
>> /mnt/sdb/qemu-new/qemu_test/qemu/qapi/qmp-dispatch.c:175
>>     #6 0x55d2c52f1430 in monitor_qmp_dispatch 
>> /mnt/sdb/qemu-new/qemu_test/qemu/monitor/qmp.c:145
>>     #7 0x55d2c52f3087 in monitor_qmp_bh_dispatcher 
>> /mnt/sdb/qemu-new/qemu_test/qemu/monitor/qmp.c:234
>>     #8 0x55d2c58e6153 in aio_bh_call 
>> /mnt/sdb/qemu-new/qemu_test/qemu/util/async.c:136
>>
>> Fixes: 5f07c4d60d091320186e7b0edaf9ed2cc16b2d1e
>> Reported-by: Euler Robot <address@hidden>
>> Signed-off-by: Pan Nengyuan <address@hidden>
>
> Reviewed-by: Markus Armbruster <address@hidden>