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

[Jun Zhao]

On 2017/3/8 16:58, Mark Thompson wrote:
> 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)

Mark, can you give the test command for this crash? It's will help me quick reproduce/debug this issue.Tks.