[FFmpeg-devel] [PATCH] libswresample/swresamplec: Err num(negative-size) was used as a function parameter

[Yy]

> 2021年12月7日 下午7:25，Michael Niedermayer <michael at niedermayer.cc> 写道：
> 
> On Mon, Dec 06, 2021 at 08:21:42PM +0800, Yu Yang wrote:
>> If cannot allocate memory, ERROR(ENOMEM) '-12' as a parameter will be constantly being returned.
>> When run resample() firstly, negative size param would cause buffer-overflow and SEGV in swri_rematrix(). 
>> When run swri_rematrix() firstly, resample() would not cause error but Err num as a wrong parameter passing.
>> Err num should be returned immediately. And remove assert to ensure the return of the error code.
>> 
>> coredump info:
>>    #0 0x499517 in posix_memalign (/home/r1/ffmpeg/ffmpeg_4.4.1+0x499517)
>>    #1 0x6c1f0b4 in av_malloc /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libavutil/mem.c:86:9
>>    #2 0x6c208fe in av_mallocz /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libavutil/mem.c:239:17
>>    #3 0x6c207ad in av_mallocz_array /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libavutil/mem.c:195:12
>>    #4 0x654b2e5 in swri_realloc_audio /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libswresample/swresample.c:418:14
>>    #5 0x654f9a1 in swr_convert_internal /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libswresample/swresample.c:601:17
>>    #6 0x654d2c0 in swr_convert /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libswresample/swresample.c:766:19
>>    #7 0x186cf56 in flush_frame /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libavfilter/af_aresample.c:251:13
>>    #8 0x186a454 in request_frame /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libavfilter/af_aresample.c:288:20
>>    #9 0x787d9c in ff_request_frame_to_filter /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libavfilter/avfilter.c:459:15
>>    #10 0x7877f1 in forward_status_change /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libavfilter/avfilter.c:1257:19
>>    #11 0x77ed7e in ff_filter_activate_default /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libavfilter/avfilter.c:1288:20
>>    #12 0x77e4e1 in ff_filter_activate /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libavfilter/avfilter.c:1441:11
>>    #13 0x793b3f in ff_filter_graph_run_once /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libavfilter/avfiltergraph.c:1403:12
>>    #14 0x7a7bee in get_frame_internal /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libavfilter/buffersink.c:131:19
>>    #15 0x7a7287 in av_buffersink_get_frame_flags /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libavfilter/buffersink.c:142:12
>>    #16 0x792888 in avfilter_graph_request_oldest /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libavfilter/avfiltergraph.c:1356:17
>>    #17 0x5d07df in transcode_from_filter /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/fftools/ffmpeg.c:4639:11
>>    #18 0x59e557 in transcode_step /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/fftools/ffmpeg.c:4729:20
>>    #19 0x593970 in transcode /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/fftools/ffmpeg.c:4805:15
>>    #20 0x58f7a4 in main /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/fftools/ffmpeg.c:5010:9
>>    #21 0x7f6fd2dee0b2 in __libc_start_main /build/glibc-eX1tMB/glibc-2.31/csu/../csu/libc-start.c:308:16
>> 
>> SUMMARY: AddressSanitizer: negative-size-param (/home/r1/ffmpeg/ffmpeg_4.4.1+0x497e67) in __asan_memcpy
>> 
>> Reported-by: TOTE Robot <oslab at tsinghua.edu.cn>
>> Signed-off-by: Yu Yang <young_chelsea at 163.com>
>> ---
>> libswresample/swresample.c | 6 +++++-
>> 1 file changed, 5 insertions(+), 1 deletion(-)
>> 
>> diff --git a/libswresample/swresample.c b/libswresample/swresample.c
>> index c03fe5528f..92ab6a9148 100644
>> --- a/libswresample/swresample.c
>> +++ b/libswresample/swresample.c
>> @@ -644,6 +644,8 @@ static int swr_convert_internal(struct SwrContext *s, AudioData *out, int out_co
>>     if(s->resample_first){
> 
>>         if(postin != midbuf)
>>             out_count= resample(s, midbuf, out_count, postin, in_count);
>> +            if (out_count < 0)
>> +                return out_count;
> 
> this doesnt look right
I could not understand your relpy. Do you mean this bug not exist, or this patch not good ? 
> 
> [...]
> -- 
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
> 
> No snowflake in an avalanche ever feels responsible. -- Voltaire
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".