From 5a5f12e3b3f2177ede5839ff4141228666b8436f Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 4 Aug 2019 17:10:18 +0200 Subject: [PATCH] avcodec/vorbisdec: Implement vr->classifications = 1 It appears no valid file uses this, so this is not testable with a valid file. Fixes: assertion failure Fixes: 16187/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VORBIS_fuzzer-5638880618872832 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/vorbisdec.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/libavcodec/vorbisdec.c b/libavcodec/vorbisdec.c index 793f079737..1045d574b1 100644 --- a/libavcodec/vorbisdec.c +++ b/libavcodec/vorbisdec.c @@ -1361,8 +1361,12 @@ static av_always_inline int setup_classifs(vorbis_context *vc, return AVERROR_INVALIDDATA; } - av_assert0(vr->classifications > 1); //needed for inverse[] - + if (vr->classifications == 1) { + for (i = partition_count + c_p_c - 1; i >= partition_count; i--) { + if (i < ptns_to_read) + vr->classifs[p + i] = 0; + } + } else { for (i = partition_count + c_p_c - 1; i >= partition_count; i--) { temp2 = (((uint64_t)temp) * inverse_class) >> 32; @@ -1370,6 +1374,7 @@ static av_always_inline int setup_classifs(vorbis_context *vc, vr->classifs[p + i] = temp - temp2 * vr->classifications; temp = temp2; } + } } p += ptns_to_read; }