ffmpeg | branch: master | Michael Niedermayer <michael@niedermayer.cc> | Sat Jan 19 00:00:49 2019 +0100| [eb1f95eb355ff9477e70bedfe0602c2380b05969] | committer: Michael Niedermayer avcodec/rscc: Avoid returning frames that have nearly no undamaged pixels in them Fixes: Timeout Fixes: 12192/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RSCC_fuzzer-6279038004363264 Before: clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RSCC_fuzzer-6279038004363264 in 15423 ms After: clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RSCC_fuzzer-6279038004363264 in 190 ms Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=eb1f95eb355ff9477e...

libavcodec/rscc.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/libavcodec/rscc.c b/libavcodec/rscc.c index 7921f149ed..e4b51973d8 100644 --- a/libavcodec/rscc.c +++ b/libavcodec/rscc.c @@ -64,6 +64,7 @@ typedef struct RsccContext { /* zlib interaction */ uint8_t *inflated_buf; uLongf inflated_size; + int valid_pixels } RsccContext; static av_cold int rscc_init(AVCodecContext *avctx) @@ -347,8 +348,11 @@ static int rscc_decode_frame(AVCodecContext *avctx, void *data, } memcpy (frame->data[1], ctx->palette, AVPALETTE_SIZE); } - - *got_frame = 1; + // We only return a picture when enough of it is undamaged, this avoids copying nearly broken frames around + if (ctx->valid_pixels < ctx->inflated_size) + ctx->valid_pixels += pixel_size; + if (ctx->valid_pixels >= ctx->inflated_size * (100 - avctx->discard_damaged_percentage) / 100) + *got_frame = 1; ret = avpkt->size; end: