See [1] for a patchset that is intended to address the coverity issue and simplify error handling.
[1] https://patchwork.ffmpeg.org/project/ffmpeg/patch/20220907200233.21255-1-...@sandflow.com/ On Sat, Aug 27, 2022 at 10:25 AM Pierre-Anthony Lemieux <p...@sandflow.com> wrote: > > On Sat, Aug 27, 2022 at 5:25 AM Steven Liu <lingjiujia...@gmail.com> wrote: > > > > Pierre-Anthony Lemieux <p...@sandflow.com> 于2022年8月27日周六 00:06写道： > > > > > > 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. > > Can imf add or remove track when processing? Looks like the live > > streaming change resolution or bitrate when playing. > > The number of tracks is fixed and determined when the Composition > Playlist (CPL) is parsed. > > > > > > > > > > > > > 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". > > _______________________________________________ > > 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".
