From patchwork Sun Mar 10 00:40:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 12278 Return-Path: X-Original-To: patchwork@ffaux-bg.ffmpeg.org Delivered-To: patchwork@ffaux-bg.ffmpeg.org Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by ffaux.localdomain (Postfix) with ESMTP id 4ED33449180 for ; Sun, 10 Mar 2019 02:42:58 +0200 (EET) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 301C868A7A0; Sun, 10 Mar 2019 02:42:58 +0200 (EET) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-dmta-pe07-1.mx.upcmail.net (vie01a-dmta-pe07-1.mx.upcmail.net [84.116.36.17]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id C323368A6E0 for ; Sun, 10 Mar 2019 02:42:51 +0200 (EET) Received: from [172.31.216.235] (helo=vie01a-pemc-psmtp-pe12.mail.upcmail.net) by vie01a-dmta-pe07.mx.upcmail.net with esmtp (Exim 4.88) (envelope-from ) id 1h2mYE-0007n8-31 for ffmpeg-devel@ffmpeg.org; Sun, 10 Mar 2019 01:42:50 +0100 Received: from localhost ([213.47.41.20]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id 2mXFh9XL3xLwq2mXFhXx97; Sun, 10 Mar 2019 01:41:50 +0100 X-Env-Mailfrom: michael@niedermayer.cc X-Env-Rcptto: ffmpeg-devel@ffmpeg.org X-SourceIP: 213.47.41.20 X-CNFS-Analysis: v=2.3 cv=WaxylHpX c=1 sm=1 tr=0 a=I1eytVlZLDX1BM2VTtTtSw==:117 a=I1eytVlZLDX1BM2VTtTtSw==:17 a=MKtGQD3n3ToA:10 a=1oJP67jkp3AA:10 a=GEAsPZ9sns4A:10 a=ZZnuYtJkoWoA:10 a=nZOtpAppAAAA:20 a=UolrJaiDYVeio_kmPYgA:9 a=1fhp2MxaeJtTNGEnv6mo:22 a=pHzHmUro8NiASowvMSCR:22 a=n87TN5wuljxrRezIQYnT:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Sun, 10 Mar 2019 01:40:59 +0100 Message-Id: <20190310004100.3811-1-michael@niedermayer.cc> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 X-CMAE-Envelope: MS4wfLWOl1uINFJV+Ks4DwEKKcN0O0n+cEXJzhQNgB0/YXjL52Km46Wv1PixTNgvEZBW/PQZuYOaTBU/2EMALhOWruKWnnfQZ/e/tFqfZdQ0FGhWrA14TQW4 f8svwlosCPLY1hrbDJ8spViu7vP8KMAURGlGVbahFBXbgFJ6cJ53bjxB Subject: [FFmpeg-devel] [PATCH 1/2] avcodec/mpeg4videodec: Check idx in mpeg4_decode_studio_block() X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Fixes: Out of array access Fixes: 13500/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG4_fuzzer-5769760178962432 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/mpeg4videodec.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c index ecd028a87c..bb9f1e3f2c 100644 --- a/libavcodec/mpeg4videodec.c +++ b/libavcodec/mpeg4videodec.c @@ -1899,14 +1899,20 @@ static int mpeg4_decode_studio_block(MpegEncContext *s, int32_t block[64], int n code >>= 1; run = (1 << (additional_code_len - 1)) + code; idx += run; + if (idx > 63) + return AVERROR_INVALIDDATA; j = scantable[idx++]; block[j] = sign ? 1 : -1; } else if (group >= 13 && group <= 20) { /* Level value (Table B.49) */ + if (idx > 63) + return AVERROR_INVALIDDATA; j = scantable[idx++]; block[j] = get_xbits(&s->gb, additional_code_len); } else if (group == 21) { /* Escape */ + if (idx > 63) + return AVERROR_INVALIDDATA; j = scantable[idx++]; additional_code_len = s->avctx->bits_per_raw_sample + s->dct_precision + 4; flc = get_bits(&s->gb, additional_code_len);