ffmpeg | branch: release/3.2 | Michael Niedermayer <mich...@niedermayer.cc> | Thu Nov 29 02:32:10 2018 +0100| [aa5190d54adb21caac60e3306e4691c728e67208] | committer: Michael Niedermayer
avcodec/msmpeg4dec: Skip frame if its smaller than 1/8 of the minimal size Frames that small are not valid and of limited use for error concealment, while being very computationally intensive to process. Fixes: Timeout Fixes: 11318/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MSMPEG4V1_fuzzer-5710884555456512 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> (cherry picked from commit 09ec182864d41c990bc18f620eabb77444aeff57) Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=aa5190d54adb21caac60e3306e4691c728e67208 --- libavcodec/msmpeg4dec.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/libavcodec/msmpeg4dec.c b/libavcodec/msmpeg4dec.c index 26f292806f..e0f07ee550 100644 --- a/libavcodec/msmpeg4dec.c +++ b/libavcodec/msmpeg4dec.c @@ -409,6 +409,14 @@ int ff_msmpeg4_decode_picture_header(MpegEncContext * s) { int code; + // at minimum one bit per macroblock is required at least in a valid frame, + // we discard frames much smaller than this. Frames smaller than 1/8 of the + // smallest "black/skip" frame generally contain not much recoverable content + // while at the same time they have the highest computational requirements + // per byte + if (get_bits_left(&s->gb) * 8LL < (s->width+15)/16 * ((s->height+15)/16)) + return AVERROR_INVALIDDATA; + if(s->msmpeg4_version==1){ int start_code = get_bits_long(&s->gb, 32); if(start_code!=0x00000100){ _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog
