[FFmpeg-devel] [PATCH V2] vf_hwupload: Add missing return value check

[Mark Thompson]

On 08/03/17 01:25, Jun Zhao wrote:
> ping ?
> 
> On 2017/3/3 9:35, Jun Zhao wrote:
>> V2: Fix the potential memory leak.2
>>
>> From eb283d277679b5dac9c43e8d3c98bcc9367b592f Mon Sep 17 00:00:00 2001
>> From: Jun Zhao <jun.zhao at intel.com>
>> Date: Fri, 3 Mar 2017 09:25:53 +0800
>> Subject: [PATCH] vf_hwupload: Add missing return value check
>> 
>> Add missing return value checks and fix the potential memory leak.
>> 
>> Signed-off-by: Jun Zhao <jun.zhao at intel.com>
>> ---
>>  libavfilter/vf_hwupload.c | 18 ++++++++++++------
>>  1 file changed, 12 insertions(+), 6 deletions(-)
>> 
>> diff --git a/libavfilter/vf_hwupload.c b/libavfilter/vf_hwupload.c
>> index 08af2dd..4b63a2a 100644
>> --- a/libavfilter/vf_hwupload.c
>> +++ b/libavfilter/vf_hwupload.c
>> @@ -74,22 +74,28 @@ static int hwupload_query_formats(AVFilterContext *avctx)
>>      if (input_pix_fmts) {
>>          for (i = 0; input_pix_fmts[i] != AV_PIX_FMT_NONE; i++) {
>>              err = ff_add_format(&input_formats, input_pix_fmts[i]);
>> -            if (err < 0) {
>> -                ff_formats_unref(&input_formats);
>> +            if (err < 0)
>>                  goto fail;
>> -            }
>>          }
>>      }
>>  
>> -    ff_formats_ref(input_formats, &avctx->inputs[0]->out_formats);
>> +    if ((err = ff_formats_ref(input_formats, &avctx->inputs[0]->out_formats)) < 0)
>> +        goto fail;
>>  
>> -    ff_formats_ref(ff_make_format_list(output_pix_fmts),
>> -                   &avctx->outputs[0]->in_formats);
>> +    if ((err = ff_formats_ref(ff_make_format_list(output_pix_fmts),
>> +                              &avctx->outputs[0]->in_formats)) < 0) {
>> +        ff_formats_unref(&input_formats);
>> +        goto fail;
>> +    }
>>  
>>      av_hwframe_constraints_free(&constraints);
>>      return 0;
>>  
>>  fail:
>> +    if (input_formats) {
>> +        av_free(input_formats->formats);
>> +        av_free(input_formats);
>> +    }
>>      av_buffer_unref(&ctx->hwdevice_ref);
>>      av_hwframe_constraints_free(&constraints);
>>      return err;
>> -- 
>> 2.9.3
>> 

Crashes if the second ff_formats_ref() fails:

==32719== Invalid read of size 8
==32719==    at 0x23F6E6: ff_formats_unref (formats.c:478)
==32719==    by 0x22A028: free_link (avfilter.c:783)
==32719==    by 0x22A103: avfilter_free (avfilter.c:805)
==32719==    by 0x22C2EF: avfilter_graph_free (avfiltergraph.c:123)
==32719==    by 0x1EF08C: cleanup_filtergraph (ffmpeg_filter.c:994)
==32719==    by 0x1EFA81: configure_filtergraph (ffmpeg_filter.c:1168)
==32719==    by 0x1F7B48: ifilter_send_frame (ffmpeg.c:2193)
==32719==    by 0x1F7DC8: send_frame_to_filters (ffmpeg.c:2278)
==32719==    by 0x1F8A89: decode_video (ffmpeg.c:2469)
==32719==    by 0x1F9375: process_input_packet (ffmpeg.c:2614)
==32719==    by 0x1FFC8A: process_input (ffmpeg.c:4350)
==32719==    by 0x200104: transcode_step (ffmpeg.c:4461)
==32719==  Address 0x12f78798 is 24 bytes inside a block of size 32 free'd
==32719==    at 0x4C2CDDB: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==32719==    by 0x13BDC21: av_free (mem.c:239)
==32719==    by 0x23F7E8: ff_formats_unref (formats.c:478)
==32719==    by 0x2F8681: hwupload_query_formats (vf_hwupload.c:87)
==32719==    by 0x22CA9C: filter_query_formats (avfiltergraph.c:317)
==32719==    by 0x22D040: query_formats (avfiltergraph.c:445)
==32719==    by 0x22F368: graph_config_formats (avfiltergraph.c:1159)
==32719==    by 0x22F81A: avfilter_graph_config (avfiltergraph.c:1270)
==32719==    by 0x1EF688: configure_filtergraph (ffmpeg_filter.c:1096)
==32719==    by 0x1F7B48: ifilter_send_frame (ffmpeg.c:2193)
==32719==    by 0x1F7DC8: send_frame_to_filters (ffmpeg.c:2278)
==32719==    by 0x1F8A89: decode_video (ffmpeg.c:2469)
==32719==  Block was alloc'd at
==32719==    at 0x4C2DF16: memalign (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==32719==    by 0x4C2E021: posix_memalign (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==32719==    by 0x13BD9DD: av_malloc (mem.c:97)
==32719==    by 0x13BDC75: av_mallocz (mem.c:254)
==32719==    by 0x23EF33: ff_make_format_list (formats.c:285)
==32719==    by 0x2F85A2: hwupload_query_formats (vf_hwupload.c:69)
==32719==    by 0x22CA9C: filter_query_formats (avfiltergraph.c:317)
==32719==    by 0x22D040: query_formats (avfiltergraph.c:445)
==32719==    by 0x22F368: graph_config_formats (avfiltergraph.c:1159)
==32719==    by 0x22F81A: avfilter_graph_config (avfiltergraph.c:1270)
==32719==    by 0x1EF688: configure_filtergraph (ffmpeg_filter.c:1096)
==32719==    by 0x1F7B48: ifilter_send_frame (ffmpeg.c:2193)

... more invalid reads ...

==32719== Process terminating with default action of signal 11 (SIGSEGV)
==32719==  Access not within mapped region at address 0x0
==32719==    at 0x13BDC35: av_freep (mem.c:247)
==32719==    by 0x23FBF6: ff_set_common_channel_layouts (formats.c:552)
==32719==    by 0x240100: default_query_formats_common (formats.c:586)
==32719==    by 0x24015C: ff_default_query_formats (formats.c:599)
==32719==    by 0x22D051: query_formats (avfiltergraph.c:447)
==32719==    by 0x22F368: graph_config_formats (avfiltergraph.c:1159)
==32719==    by 0x22F81A: avfilter_graph_config (avfiltergraph.c:1270)
==32719==    by 0x1EF688: configure_filtergraph (ffmpeg_filter.c:1096)
==32719==    by 0x1F68C5: flush_encoders (ffmpeg.c:1876)
==32719==    by 0x20032E: transcode (ffmpeg.c:4538)
==32719==    by 0x20097D: main (ffmpeg.c:4720)