Re: [Qemu-devel] [PATCH] json-parser: Fix potential NULL pointer segfault

[Stefan Weil <sw@weilnetz.de>]

Am 03.09.2012 18:41, schrieb Luiz Capitulino:
> On Sat,  1 Sep 2012 12:52:58 +0200
> Stefan Weil <sw@weilnetz.de> wrote:
>
>> Report from smatch:
>> json-parser.c:474 parse_object(62) error: potential null derefence 'dict'.
>> json-parser.c:553 parse_array(75) error: potential null derefence 'list'.
>>
>> Label out can be called with list == NULL.
>>
>> Signed-off-by: Stefan Weil <sw@weilnetz.de>
>> ---
>>   json-parser.c |    8 ++++++--
>>   1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/json-parser.c b/json-parser.c
>> index 457291b..c31c759 100644
>> --- a/json-parser.c
>> +++ b/json-parser.c
>> @@ -471,7 +471,9 @@ static QObject *parse_object(JSONParserContext *ctxt, va_list *ap)
>>   
>>   out:
>>       parser_context_restore(ctxt, saved_ctxt);
>> -    QDECREF(dict);
>> +    if (dict) {
>> +        QDECREF(dict);
>> +    }
>
> I prefer changing QDECREF() to a nop if obj is NULL.

That's fine for me, too. If everybody agrees, I'll send two new
patches: one to change QDECREF, one to remove the if statements
from other code locations which use the same pattern as
my original patch.

Cheers,

- sw