On 9/22/23, Michael Niedermayer <mich...@niedermayer.cc> wrote: > On Thu, Sep 21, 2023 at 08:14:31PM +0200, Paul B Mahol wrote: >> On Thu, Sep 21, 2023 at 8:09 PM Michael Niedermayer >> <mich...@niedermayer.cc> >> wrote: >> >> > Fixes: out of array access >> > Fixes: >> > 62164/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_OSQ_fuzzer-6227491892887552 >> > Fixes: >> > 62164/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_OSQ_fuzzer-6268561729126400 >> > Fixes: >> > 62164/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_OSQ_fuzzer-6414805046788096 >> > Fixes: >> > 62164/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_OSQ_fuzzer-6538151088488448 >> > Fixes: >> > 62164/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_OSQ_fuzzer-6608131540779008 >> > >> > Found-by: continuous fuzzing process >> > https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg >> > Signed-off-by >> > <https://github.com/google/oss-fuzz/tree/master/projects/ffmpegSigned-off-by>: >> > Michael Niedermayer <mich...@niedermayer.cc> >> > --- >> > libavcodec/osq.c | 3 +++ >> > 1 file changed, 3 insertions(+) >> > >> > diff --git a/libavcodec/osq.c b/libavcodec/osq.c >> > index e7f11691d2e..bcc75fef6fc 100644 >> > --- a/libavcodec/osq.c >> > +++ b/libavcodec/osq.c >> > @@ -408,6 +408,9 @@ static int osq_receive_frame(AVCodecContext *avctx, >> > AVFrame *frame) >> > GetBitContext *gb = &s->gb; >> > int ret, n; >> > >> > + if (s->pkt_offset > s->pkt->size) >> > + s->pkt_offset = 0; >> > >> >> This is more hack than real fix. > > why ? > > pkt->size is reset outside the codec, so either it needs to be > checked on codec entry or the codec should not use > internal->in_pkt and expect its size to be conserved > or implement flush() or something > > ff_decode_flush_buffers() for example will clear teh packet > > if you prefer i can implement flush() and reset pkt_offset in it > that probably would achieve teh same > just say if you prefer that ?
Yup, that is much cleaner, go ahead with that solution with flush(). I forgot about flush() case completely. > > thx > > [...] > -- > Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB > > When the tyrant has disposed of foreign enemies by conquest or treaty, and > there is nothing more to fear from them, then he is always stirring up > some war or other, in order that the people may require a leader. -- Plato > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
