On Fri, Aug 26, 2022 at 9:01 AM Andreas Rheinhardt <andreas.rheinha...@outlook.com> wrote: > > Pierre-Anthony Lemieux: > > 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? > > > > The typical way to do this is to add an av_assert1 or av_assert2; > but this must only be done if it is indeed ensured that the assert will > not be triggered. > > >> (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. > > > > Can't we make it true by adding the relevant checks to read_header?
Yes. > > > 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? > > > > Yes. > > >> > >>> 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". > > _______________________________________________ > 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".
