From 9e98ee41e7ef3bf02cf0de826f0293f6af0e07c0 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 19 Apr 2021 15:50:43 +0200 Subject: [PATCH] avcodec/vc1: Check remaining bits in ff_vc1_parse_frame_header() Fixes: Timeout Fixes: 33156/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WMV3_fuzzer-6259655027326976 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit 38c47615880357314ba30727a85bf7b00989706a) Signed-off-by: Michael Niedermayer --- libavcodec/vc1.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/libavcodec/vc1.c b/libavcodec/vc1.c index 9df778bcab..4297834522 100644 --- a/libavcodec/vc1.c +++ b/libavcodec/vc1.c @@ -671,6 +671,8 @@ int ff_vc1_parse_frame_header(VC1Context *v, GetBitContext* gb) if (v->s.pict_type == AV_PICTURE_TYPE_P) v->rnd ^= 1; + if (get_bits_left(gb) < 5) + return AVERROR_INVALIDDATA; /* Quantizer stuff */ pqindex = get_bits(gb, 5); if (!pqindex) @@ -763,6 +765,9 @@ int ff_vc1_parse_frame_header(VC1Context *v, GetBitContext* gb) av_log(v->s.avctx, AV_LOG_DEBUG, "MB Skip plane encoding: " "Imode: %i, Invert: %i\n", status>>1, status&1); + if (get_bits_left(gb) < 4) + return AVERROR_INVALIDDATA; + /* Hopefully this is correct for P-frames */ v->s.mv_table_index = get_bits(gb, 2); //but using ff_vc1_ tables v->cbptab = get_bits(gb, 2);