From patchwork Thu Aug 22 22:52:48 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 14673 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 C1D4B44843C for ; Fri, 23 Aug 2019 01:54:55 +0300 (EEST) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id ACDC968ACE8; Fri, 23 Aug 2019 01:54:55 +0300 (EEST) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-dmta-pe06-2.mx.upcmail.net (vie01a-dmta-pe06-2.mx.upcmail.net [84.116.36.15]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 6D18E68AC9B for ; Fri, 23 Aug 2019 01:54:48 +0300 (EEST) Received: from [172.31.216.235] (helo=vie01a-pemc-psmtp-pe12.mail.upcmail.net) by vie01a-dmta-pe06.mx.upcmail.net with esmtp (Exim 4.92) (envelope-from ) id 1i0vyh-0007mT-2f for ffmpeg-devel@ffmpeg.org; Fri, 23 Aug 2019 00:54:47 +0200 Received: from localhost ([213.47.41.20]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id 0vxji21Alwlys0vxjifZnC; Fri, 23 Aug 2019 00:53:47 +0200 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=E5OzWpVl c=1 sm=1 tr=0 a=I1eytVlZLDX1BM2VTtTtSw==:117 a=I1eytVlZLDX1BM2VTtTtSw==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=MKtGQD3n3ToA:10 a=1oJP67jkp3AA:10 a=GEAsPZ9sns4A:10 a=ZZnuYtJkoWoA:10 a=nZOtpAppAAAA:20 a=omr8hIzXdkkVqmg5PxkA:9 a=1fhp2MxaeJtTNGEnv6mo:22 a=Z5ABNNGmrOfJ6cZ5bIyy:22 a=QOGEsqRv6VhmHaoFNykA:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Fri, 23 Aug 2019 00:52:48 +0200 Message-Id: <20190822225248.20952-2-michael@niedermayer.cc> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190822225248.20952-1-michael@niedermayer.cc> References: <20190822225248.20952-1-michael@niedermayer.cc> MIME-Version: 1.0 X-CMAE-Envelope: MS4wfOKaL2gdzBmnEj1n4nwnVJK2dg/D+ptUAwOpc4m0SUkVbKvoJ+tqUS0cnWuRLlr/Cxl4GVuf4o5G8SGSAlMwitB7LRLMzC5TVf1j9h0dNanUbWNgyoH8 gmKjGVK2M8vzFHAwJ/2ITTGJTXzP0qPu2i8oBmS3jFnqAHPL0ScSxZKh Subject: [FFmpeg-devel] [PATCH 2/2] avcodec/mpeg4videodec: Fix integer overflow 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: signed integer overflow: 24023040 * 112 cannot be represented in type 'int' Fixes: 16570/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG4_fuzzer-5173275211071488 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/mpeg4videodec.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c index b6f2ae7b7b..25f528d59e 100644 --- a/libavcodec/mpeg4videodec.c +++ b/libavcodec/mpeg4videodec.c @@ -1826,6 +1826,7 @@ static int mpeg4_decode_studio_block(MpegEncContext *s, int32_t block[64], int n uint32_t flc; const int min = -1 * (1 << (s->avctx->bits_per_raw_sample + 6)); const int max = ((1 << (s->avctx->bits_per_raw_sample + 6)) - 1); + int shift = 3 - s->dct_precision; mismatch = 1; @@ -1921,7 +1922,7 @@ static int mpeg4_decode_studio_block(MpegEncContext *s, int32_t block[64], int n else block[j] = flc; } - block[j] = ((8 * 2 * block[j] * quant_matrix[j] * s->qscale) >> s->dct_precision) / 32; + block[j] = ((block[j] * quant_matrix[j] * s->qscale) * (1 << shift)) / 16; block[j] = av_clip(block[j], min, max); mismatch ^= block[j]; }