From patchwork Fri Jun 21 23:29:32 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 13672 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 3421644841F for ; Sat, 22 Jun 2019 02:31:35 +0300 (EEST) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id F2BEE68AB2F; Sat, 22 Jun 2019 02:31:34 +0300 (EEST) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-dmta-pe08-2.mx.upcmail.net (vie01a-dmta-pe08-2.mx.upcmail.net [84.116.36.21]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 23DB168A9F3 for ; Sat, 22 Jun 2019 02:31:23 +0300 (EEST) Received: from [172.31.216.235] (helo=vie01a-pemc-psmtp-pe12.mail.upcmail.net) by vie01a-dmta-pe08.mx.upcmail.net with esmtp (Exim 4.92) (envelope-from ) id 1heT05-0001V6-4F for ffmpeg-devel@ffmpeg.org; Sat, 22 Jun 2019 01:31:21 +0200 Received: from localhost ([213.47.41.20]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id eSz7h1dAA5D5NeSz7h47LF; Sat, 22 Jun 2019 01:30:21 +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=bu8y+3Si 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=xd8YuhrVnJ1zSC3OTAIA:9 a=1fhp2MxaeJtTNGEnv6mo:22 a=pHzHmUro8NiASowvMSCR:22 a=nt3jZW36AmriUCFCBwmW:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Sat, 22 Jun 2019 01:29:32 +0200 Message-Id: <20190621232936.11052-2-michael@niedermayer.cc> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190621232936.11052-1-michael@niedermayer.cc> References: <20190621232936.11052-1-michael@niedermayer.cc> MIME-Version: 1.0 X-CMAE-Envelope: MS4wfCcihExjNgoXKSec90Z2C6YDU3nvY37Ers1xHZwAExslgHPgz+Tj8MGakEF91Yh4IN1Z3eYng2u2N3knug2mRV3Wp0XWARnhSiAitjJzj2EzPLW4wc4d 3M6rFYl9PBQpWqD4O1QZPWd5TqORcA+gvRyY+3B8YXFrbBWAiOEZd9kO Subject: [FFmpeg-devel] [PATCH 2/6] avcodec/ffwavesynth: Simplify lcg_seek(), avoid negative case 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: negation of -9223372036854775808 cannot be represented in type 'int64_t' (aka 'long'); cast to an unsigned type to negate this value to itself Fixes: 15289/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FFWAVESYNTH_fuzzer-5709034499342336 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/ffwavesynth.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/libavcodec/ffwavesynth.c b/libavcodec/ffwavesynth.c index cf8c780f3e..b2cc7c8fc1 100644 --- a/libavcodec/ffwavesynth.c +++ b/libavcodec/ffwavesynth.c @@ -113,18 +113,12 @@ static uint32_t lcg_next(uint32_t *s) return *s; } -static void lcg_seek(uint32_t *s, int64_t dt) +static void lcg_seek(uint32_t *s, uint32_t dt) { uint32_t a, c, t = *s; - if (dt >= 0) { - a = LCG_A; - c = LCG_C; - } else { /* coefficients for a step backward */ - a = LCG_AI; - c = (uint32_t)(-LCG_AI * LCG_C); - dt = -dt; - } + a = LCG_A; + c = LCG_C; while (dt) { if (dt & 1) t = a * t + c;