From patchwork Sat May 2 21:08:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 19445 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 B16E2449C24 for ; Sun, 3 May 2020 00:09:19 +0300 (EEST) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id A1DE468C1F9; Sun, 3 May 2020 00:09:19 +0300 (EEST) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-dmta-pe06-1.mx.upcmail.net (vie01a-dmta-pe06-1.mx.upcmail.net [84.116.36.14]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 6F6F368BF42 for ; Sun, 3 May 2020 00:09:12 +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 1jUzNo-0002GS-0J for ffmpeg-devel@ffmpeg.org; Sat, 02 May 2020 23:09:12 +0200 Received: from localhost ([213.47.68.29]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id UzMqjHbq46Jy6UzMqj6TIu; Sat, 02 May 2020 23:08:12 +0200 X-Env-Mailfrom: michael@niedermayer.cc X-Env-Rcptto: ffmpeg-devel@ffmpeg.org X-SourceIP: 213.47.68.29 X-CNFS-Analysis: v=2.3 cv=GKl27dFK c=1 sm=1 tr=0 a=2hcxjKEKjp0CzLx6oWAm4g==:117 a=2hcxjKEKjp0CzLx6oWAm4g==:17 a=MKtGQD3n3ToA:10 a=1oJP67jkp3AA:10 a=GEAsPZ9sns4A:10 a=ZZnuYtJkoWoA:10 a=nZOtpAppAAAA:20 a=s4eig8V5xcBP0z2NLXcA:9 a=1fhp2MxaeJtTNGEnv6mo:22 a=Z5ABNNGmrOfJ6cZ5bIyy:22 a=UDnyf2zBuKT2w-IlGP_r:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Sat, 2 May 2020 23:08:07 +0200 Message-Id: <20200502210807.18754-2-michael@niedermayer.cc> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200502210807.18754-1-michael@niedermayer.cc> References: <20200502210807.18754-1-michael@niedermayer.cc> X-CMAE-Envelope: MS4wfLd9AT4+YG3ZF1oO9Bx/t4HeWs4g7NvXSxIuPZHlnEKLg50HdCAA4HowKO4/hwE4hYrY5k2Q4DEW5u4G73IzxZHEsH7+3vCPp6K/q7p/PiDDvG3LC6s5 7wCLcydIOHNwj27U2IkjGDIyu7y+zIXGrltknOdDKbRtDqtZ5hfB9883 Subject: [FFmpeg-devel] [PATCH 2/2] avcodec/xvididct: Fix integer overflow in idct_row() 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 MIME-Version: 1.0 Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Fixes: signed integer overflow: -1238335488 + -1003634688 cannot be represented in type 'int' Fixes: 21649/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MJPEG_fuzzer-5112005765890048 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/xvididct.c | 36 ++++++++++++++++++------------------ 1 file changed, 18 insertions(+), 18 deletions(-) diff --git a/libavcodec/xvididct.c b/libavcodec/xvididct.c index 14116bd6d3..360deb3244 100644 --- a/libavcodec/xvididct.c +++ b/libavcodec/xvididct.c @@ -115,24 +115,24 @@ static int idct_row(short *in, const int *const tab, int rnd) in[6] = a1; } else { const int k = c4 * in[0] + rnd; - const int a0 = k + c2 * in[2] + c4 * in[4] + c6 * in[6]; - const int a1 = k + c6 * in[2] - c4 * in[4] - c2 * in[6]; - const int a2 = k - c6 * in[2] - c4 * in[4] + c2 * in[6]; - const int a3 = k - c2 * in[2] + c4 * in[4] - c6 * in[6]; - - const int b0 = c1 * in[1] + c3 * in[3] + c5 * in[5] + c7 * in[7]; - const int b1 = c3 * in[1] - c7 * in[3] - c1 * in[5] - c5 * in[7]; - const int b2 = c5 * in[1] - c1 * in[3] + c7 * in[5] + c3 * in[7]; - const int b3 = c7 * in[1] - c5 * in[3] + c3 * in[5] - c1 * in[7]; - - in[0] = (a0 + b0) >> ROW_SHIFT; - in[1] = (a1 + b1) >> ROW_SHIFT; - in[2] = (a2 + b2) >> ROW_SHIFT; - in[3] = (a3 + b3) >> ROW_SHIFT; - in[4] = (a3 - b3) >> ROW_SHIFT; - in[5] = (a2 - b2) >> ROW_SHIFT; - in[6] = (a1 - b1) >> ROW_SHIFT; - in[7] = (a0 - b0) >> ROW_SHIFT; + const unsigned int a0 = k + c2 * in[2] + c4 * in[4] + c6 * in[6]; + const unsigned int a1 = k + c6 * in[2] - c4 * in[4] - c2 * in[6]; + const unsigned int a2 = k - c6 * in[2] - c4 * in[4] + c2 * in[6]; + const unsigned int a3 = k - c2 * in[2] + c4 * in[4] - c6 * in[6]; + + const unsigned int b0 = c1 * in[1] + c3 * in[3] + c5 * in[5] + c7 * in[7]; + const unsigned int b1 = c3 * in[1] - c7 * in[3] - c1 * in[5] - c5 * in[7]; + const unsigned int b2 = c5 * in[1] - c1 * in[3] + c7 * in[5] + c3 * in[7]; + const unsigned int b3 = c7 * in[1] - c5 * in[3] + c3 * in[5] - c1 * in[7]; + + in[0] = (int)(a0 + b0) >> ROW_SHIFT; + in[1] = (int)(a1 + b1) >> ROW_SHIFT; + in[2] = (int)(a2 + b2) >> ROW_SHIFT; + in[3] = (int)(a3 + b3) >> ROW_SHIFT; + in[4] = (int)(a3 - b3) >> ROW_SHIFT; + in[5] = (int)(a2 - b2) >> ROW_SHIFT; + in[6] = (int)(a1 - b1) >> ROW_SHIFT; + in[7] = (int)(a0 - b0) >> ROW_SHIFT; } return 1; }