[FFmpeg-devel] [PATCH] lavf/oggparseflac: Free flac extradata before reallocating.

[Matthew Wolenetz]

Perhaps true, but there are a ton of paths to ff_alloc_extradata that are
not included in Chromium. Such a wider, general, fix seems more appropriate
to land upstream first with more testing.
For now, this is a particular known case that's occurring in Chromium that
needs fixing.

On Mon, Mar 5, 2018 at 2:10 PM, James Almer <jamrial at gmail.com> wrote:

> On 3/5/2018 6:54 PM, Matthew Wolenetz wrote:
> >
> > 0001-lavf-oggparseflac-Free-flac-extradata-before-realloc.patch
> >
> >
> > From 5d28b92d9d164b104e9a47b8183cd7ddedfde366 Mon Sep 17 00:00:00 2001
> > From: Matt Wolenetz <wolenetz at chromium.org>
> > Date: Mon, 5 Mar 2018 12:36:28 -0800
> > Subject: [PATCH] lavf/oggparseflac: Free flac extradata before
> reallocating.
> >
> > Otherwise ff_alloc_extradata() just leaks any existing allocated
> > memory.
>
> Maybe ff_alloc_extradata() is the one that should free any existing
> extradata instead of littering the tree with av_freep() calls before
> every ff_alloc_extradata() call. Otherwise you'll keep patching up
> demuxers as your fuzzer generates files for them.
>
> >
> > BUG=789835
> >
> > Change-Id: I8e1c21a16749d28c7f050f5f5d8bffda3b419638
> > Reviewed-on: https://chromium-review.googlesource.com/949415
> > Reviewed-by: Xiaohan Wang <xhwang at chromium.org>
> > ---
> >  libavformat/oggparseflac.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/libavformat/oggparseflac.c b/libavformat/oggparseflac.c
> > index b5f1416a3c..6cb3468022 100644
> > --- a/libavformat/oggparseflac.c
> > +++ b/libavformat/oggparseflac.c
> > @@ -61,6 +61,7 @@ flac_header (AVFormatContext * s, int idx)
> >          st->codecpar->codec_id = AV_CODEC_ID_FLAC;
> >          st->need_parsing = AVSTREAM_PARSE_HEADERS;
> >
> > +        av_freep(&st->codecpar->extradata);
> >          if (ff_alloc_extradata(st->codecpar, FLAC_STREAMINFO_SIZE) < 0)
> >              return AVERROR(ENOMEM);
> >          memcpy(st->codecpar->extradata, streaminfo_start,
> st->codecpar->extradata_size);
> > -- 2.16.2.395.g2e18187dfd-goog
> >
> >
> >
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> >
>
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