On Fri, Aug 26, 2022 at 1:37 AM Andreas Rheinhardt <andreas.rheinha...@outlook.com> wrote: > > Steven Liu: > > fix CID: 1512414 > > And return AVERROR_INVALIDDATA when get_next_track_with_minimum_timestamp > > incorrect in imf_read_packet; > > > > Signed-off-by: Steven Liu <l...@chinaffmpeg.org> > > --- > > libavformat/imfdec.c | 7 +++++-- > > 1 file changed, 5 insertions(+), 2 deletions(-) > > > > diff --git a/libavformat/imfdec.c b/libavformat/imfdec.c > > index 5bbe7a53f8..08f342bc1a 100644 > > --- a/libavformat/imfdec.c > > +++ b/libavformat/imfdec.c > > @@ -697,8 +697,9 @@ static IMFVirtualTrackPlaybackCtx > > *get_next_track_with_minimum_timestamp(AVForma > > } > > } > > > > - av_log(s, AV_LOG_DEBUG, "Found next track to read: %d (timestamp: %lf > > / %lf)\n", > > - track->index, av_q2d(track->current_timestamp), > > av_q2d(minimum_timestamp)); > > + if (track) > > + av_log(s, AV_LOG_DEBUG, "Found next track to read: %d (timestamp: > > %lf / %lf)\n", > > + track->index, av_q2d(track->current_timestamp), > > av_q2d(minimum_timestamp)); > > Coverity actually complained about track being uninitialized, which this > patch does not address. And the reason it does this is that it doesn't > understand the algorithm: track will always be initialized in the first > iteration of the loop.
Is it possible to tell coverity that c->track_count > 0 is a pre-condition, or should we modify the loop/algorithm? > (If there is a first iteration of the loop -- is > this actually guaranteed? A file without tracks seems to be pretty useless.) imfdec currently assumes that (a) imf_read_packet() is not called if there are no streams/tracks and (b) a track will always be found. (b) will be true for a conformant IMF Composition, but I am not sure it can always be true for a malformed one. I think imf_read_packet() can probably be hardened. Perhaps do this as a patch separately from addressing the coverity issue? > FYI: In Coverity's analysis there are loop iterations, but it just > assumed that track is not initialized in the loop (which boils down to > saying that it presumed the tracks' current_timestamp to be invalid > (denominator 0). I hope this can't happen. > (There is btw another issue: The initialization of minimum_timestamp > presumes that int are 32bit which need not be true.) INT32_MAX -> INT_MAX should fix this right? > > > return track; > > } > > > > @@ -760,6 +761,8 @@ static int imf_read_packet(AVFormatContext *s, AVPacket > > *pkt) > > AVRational next_timestamp; > > > > track = get_next_track_with_minimum_timestamp(s); > > + if (!track) > > + return AVERROR_INVALIDDATA; > > > > ret = get_resource_context_for_timestamp(s, track, &resource); > > if (ret) > > _______________________________________________ > 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". _______________________________________________ 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".
