[FFmpeg-devel] [PATCH v1 6/8] avformat/mtv: check av_strdup() return value and fix memleak

[Steven Liu]

> 在 2019年10月10日，13:19，Steven Liu <lq at chinaffmpeg.org> 写道：
> 
> 
> 
>> 在 2019年10月10日，13:09，zhilizhao(赵志立) <quinkblack at foxmail.com> 写道：
>> 
>> 
>> 
>>> On Oct 10, 2019, at 12:59 PM, Steven Liu <lq at chinaffmpeg.org> wrote:
>>> 
>>> 
>>> 
>>>> 在 2019年10月10日，12:53，zhilizhao(赵志立) <quinkblack at foxmail.com> 写道：
>>>> 
>>>> 
>>>> 
>>>>> On Oct 10, 2019, at 11:40 AM, Steven Liu <lq at chinaffmpeg.org> wrote:
>>>>> 
>>>>> Signed-off-by: Steven Liu <lq at chinaffmpeg.org>
>>>>> ---
>>>>> libavformat/mtv.c | 13 +++++++++++--
>>>>> 1 file changed, 11 insertions(+), 2 deletions(-)
>>>>> 
>>>>> diff --git a/libavformat/mtv.c b/libavformat/mtv.c
>>>>> index 728f4a4781..c664ae14c7 100644
>>>>> --- a/libavformat/mtv.c
>>>>> +++ b/libavformat/mtv.c
>>>>> @@ -171,13 +171,19 @@ static int mtv_read_header(AVFormatContext *s)
>>>>> st->codecpar->width           = mtv->img_width;
>>>>> st->codecpar->height          = mtv->img_height;
>>>>> st->codecpar->extradata       = av_strdup("BottomUp");
>>>>> +    if (!st->codecpar->extradata) {
>>>>> +        return AVERROR(ENOMEM);
>>>>> +    }
>>>>> st->codecpar->extradata_size  = 9;
>>>>> 
>>>>> // audio - mp3
>>>>> 
>>>>> st = avformat_new_stream(s, NULL);
>>>>> -    if(!st)
>>>>> +    if(!st) {
>>>>> +        av_freep(&st->codecpar->extradata);
>>>>> +        st->codecpar->extradata_size = 0;
>>>>>     return AVERROR(ENOMEM);
>>>>> +    }
>>>> 
>>>> NULL pointer dereference?
>>> When new streams cannot be create, there have no memory, so release the st->codecpar->extradata,
>>> now st->codecpar->extradata is not NULL pointer.
>> 
>> “st”  is NULL, st->codecpar is NULL pointer dereference.
>> 
> Ah, get your point.
>> PS: I don’t think here is a memory leak.
> 
> I think it should free the st->codecpar->extradata before this st = avformat_new_stream(s, NULL);
or make deferent name of the AVStream
>> 
>> 
>>> 
>>>> 
>>>> 
>>>>> 
>>>>> avpriv_set_pts_info(st, 64, 1, MTV_AUDIO_SAMPLING_RATE);
>>>>> st->codecpar->codec_type      = AVMEDIA_TYPE_AUDIO;
>>>>> @@ -187,8 +193,11 @@ static int mtv_read_header(AVFormatContext *s)
>>>>> 
>>>>> // Jump over header
>>>>> 
>>>>> -    if(avio_seek(pb, MTV_HEADER_SIZE, SEEK_SET) != MTV_HEADER_SIZE)
>>>>> +    if(avio_seek(pb, MTV_HEADER_SIZE, SEEK_SET) != MTV_HEADER_SIZE) {
>>>>> +        av_freep(&st->codecpar->extradata);
>>>>> +        st->codecpar->extradata_size = 0;
>>>>>     return AVERROR(EIO);
>>>>> +    }
>>>>> 
>>>>> return 0;
>>>>> 
>>>>> -- 
>>>>> 2.15.1
>>>>> 
>>>>> 
>>>>> 
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>>>> 
>>>> 
>>>> 
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>>> 
>>> Thanks
>>> Steven
>>> 
>>> 
>>> 
>>> 
>>> 
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>> 
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> 
> Thanks
> Steven

Thanks
Steven