[FFmpeg-devel] [PATCH] avformat/asfdec_f: Check amount of value read

[Michael Niedermayer]

On Mon, Jul 28, 2025 at 01:10:57AM +0200, Kacper Michajlow wrote:
> On Sun, 27 Jul 2025 at 22:57, Michael Niedermayer
> <michael at niedermayer.cc> wrote:
> >
> > On Wed, Jul 23, 2025 at 05:51:35PM +0200, Kacper Michajlow wrote:
> > > On Wed, 23 Jul 2025 at 10:43, Michael Niedermayer
> > > <michael at niedermayer.cc> wrote:
> > > >
> > > > Fixes: use of uninitialized memory
> > > > Fixes: 403675492/clusterfuzz-testcase-minimized-ffmpeg_dem_ASF_fuzzer-4754281823797248
> > > >
> > > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > > > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> > > > ---
> > > >  libavformat/asfdec_f.c | 4 +++-
> > > >  1 file changed, 3 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/libavformat/asfdec_f.c b/libavformat/asfdec_f.c
> > > > index ea6e8ef4f3a..10f5dea57c3 100644
> > > > --- a/libavformat/asfdec_f.c
> > > > +++ b/libavformat/asfdec_f.c
> > > > @@ -241,7 +241,9 @@ static void get_tag(AVFormatContext *s, const char *key, int type, int len, int
> > > >          avio_get_str16le(s->pb, len, value, 2 * len + 1);
> > > >          break;
> > > >      case -1: // ASCI
> > > > -        avio_read(s->pb, value, len);
> > > > +       ;int ret = ffio_read_size(s->pb, value, len);
> > >
> > > stray ;
> >
> > no, try remove it :)
> >
> > libavformat/asfdec_f.c: In function ‘get_tag’:
> > libavformat/asfdec_f.c:244:9: error: a label can only be part of a statement and a declaration is not a statement
> >   244 |         int ret = ffio_read_size(s->pb, value, len);
> >       |         ^~~
> 
> Ah, right. It's the first line after the case statement.
> 
> I generally put it immediately after : `case -1:;`. It was looking off
> at the beginning of the line, but all good :)

ill move to after the :

thx

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The misfortune of the wise is better than the prosperity of the fool.
-- Epicurus
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