ffmpeg | branch: master | Michael Niedermayer <[email protected]> | Sat Jul 27 23:24:25 2019 +0200| [4d4734bdc881de3af0ebe5935890a81423c80fdf] | committer: Michael Niedermayer
avcodec/lcldec: Check mthread_inlen instead of cliping Clipping was added in 2009 to avoid crashes. The clipped case would produce a 2nd slice with 0 input thus also producing 0 output. Subsequent checks will cause decoder failure unless both slices have the same output length. thus the only way this would not already fail is if the output from both slices was 0 bytes. Fixes: Timeout (134sec -> 241ms) Fixes: 15599/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MSZH_fuzzer-5658127116009472 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <[email protected]> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=4d4734bdc881de3af0ebe5935890a81423c80fdf --- libavcodec/lcldec.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/libavcodec/lcldec.c b/libavcodec/lcldec.c index 104defa5f5..046cdc4f8e 100644 --- a/libavcodec/lcldec.c +++ b/libavcodec/lcldec.c @@ -190,11 +190,10 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPac ; } else if (c->flags & FLAG_MULTITHREAD) { mthread_inlen = AV_RL32(buf); - if (len < 8) { + if (len < 8 || len - 8 < mthread_inlen) { av_log(avctx, AV_LOG_ERROR, "len %d is too small\n", len); return AVERROR_INVALIDDATA; } - mthread_inlen = FFMIN(mthread_inlen, len - 8); mthread_outlen = AV_RL32(buf + 4); mthread_outlen = FFMIN(mthread_outlen, c->decomp_size); mszh_dlen = mszh_decomp(buf + 8, mthread_inlen, c->decomp_buf, c->decomp_size); _______________________________________________ ffmpeg-cvslog mailing list [email protected] https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
