[FFmpeg-devel] [PATCH 3/6] avcodec/aac/aacdec_usac: Fix memory deallocation of pl_data

[Michael Niedermayer]

On Sun, Feb 16, 2025 at 03:34:29PM +0100, Michael Niedermayer wrote:
> On Mon, Feb 10, 2025 at 05:34:38PM +0100, Andreas Rheinhardt wrote:
> > Michael Niedermayer:
> > > Fixes: double free
> > > Fixes: 393523547/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AAC_LATM_fuzzer-6740617236905984
> > > 
> > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> > > ---
> > >  libavcodec/aac/aacdec.c      | 19 +++++++++++++++++--
> > >  libavcodec/aac/aacdec_usac.c |  3 ++-
> > >  2 files changed, 19 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/libavcodec/aac/aacdec.c b/libavcodec/aac/aacdec.c
> > > index 8d50ad6d095..16259b5ada9 100644
> > > --- a/libavcodec/aac/aacdec.c
> > > +++ b/libavcodec/aac/aacdec.c
> > > @@ -421,6 +421,21 @@ static uint64_t sniff_channel_order(uint8_t (*layout_map)[3], int tags)
> > >      return layout;
> > >  }
> > >  
> > > +static void copy_oc(OutputConfiguration *dst, OutputConfiguration *src)
> > > +{
> > > +    int err = 0;
> > 
> > Seems unused.
> 
> i saw it after sending the patch
> 
> 
> > 
> > > +
> > > +    for(int i = 0; i < dst->usac.nb_elems; i++)
> > > +        av_freep(&dst->usac.elems[i].ext.pl_data);
> > > +
> > > +    *dst = *src;
> > > +
> > > +    for(int i = 0; i < dst->usac.nb_elems; i++) {
> > > +        AACUsacElemConfig *e = &dst->usac.elems[i];
> > > +        e->ext.pl_data = av_memdup(e->ext.pl_data, e->ext.pl_data_offset);
> > 
> > Unchecked allocation. Furthermore, the *dst = *src makes cleanup on
> > error here a PITA.
> 
> > Would making pl_data reference-counted (via
> > RefStruct) work instead?
> 
> likely, yes

> do you want to implement that ?

ping

thx

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Those who are best at talking, realize last or never when they are wrong.
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