From patchwork Thu Dec 3 09:11:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 24333 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 08DBB44A2C6 for ; Thu, 3 Dec 2020 11:19:37 +0200 (EET) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id E8164689FB5; Thu, 3 Dec 2020 11:19:36 +0200 (EET) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-dmta-pe03-3.mx.upcmail.net (vie01a-dmta-pe03-3.mx.upcmail.net [62.179.121.162]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id E1662689BDC for ; Thu, 3 Dec 2020 11:19:30 +0200 (EET) Received: from [172.31.216.235] (helo=vie01a-pemc-psmtp-pe12.mail.upcmail.net) by vie01a-dmta-pe03.mx.upcmail.net with esmtp (Exim 4.92) (envelope-from ) id 1kkkfI-000934-0J for ffmpeg-devel@ffmpeg.org; Thu, 03 Dec 2020 10:12:40 +0100 Received: from localhost ([213.47.68.29]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id kkeKkRzZhO4rAkkeKkw2QA; Thu, 03 Dec 2020 10:11:40 +0100 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=RNDN4Lq+ 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=tO2Lb_0KobigYYxA3EMA:9 a=1fhp2MxaeJtTNGEnv6mo:22 a=Z5ABNNGmrOfJ6cZ5bIyy:22 a=UDnyf2zBuKT2w-IlGP_r:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Thu, 3 Dec 2020 10:11:39 +0100 Message-Id: <20201203091139.14038-3-michael@niedermayer.cc> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201203091139.14038-1-michael@niedermayer.cc> References: <20201203091139.14038-1-michael@niedermayer.cc> X-CMAE-Envelope: MS4wfFv3ihHsiMTkLtyNuKr+RJz+n9Jp4tFeF7fYG/sLI8BtrR5q4TDDbILEh8Pt2BOrBAI86vRlf1pDLkj6O6jwEqdiwNdwTf2xgsKrLqkpya2ZQe22Snf9 Nbagig1/IyBwInjR5GUkeM75e1h39ck5DJ84i175b9nh1vFvuQ3TlBAr Subject: [FFmpeg-devel] [PATCH 3/3] avformat/rmdec: Reorder operations to avoid overflow 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: -2147483648 - 14 cannot be represented in type 'int' Fixes: 27659/clusterfuzz-testcase-minimized-ffmpeg_dem_RM_fuzzer-5697250168406016 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavformat/rmdec.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavformat/rmdec.c b/libavformat/rmdec.c index 004c62086d..a82519987c 100644 --- a/libavformat/rmdec.c +++ b/libavformat/rmdec.c @@ -719,9 +719,9 @@ static int rm_sync(AVFormatContext *s, int64_t *timestamp, int *flags, int *stre av_log(s, AV_LOG_WARNING, "Index size %d (%d pkts) is wrong, should be %"PRId64".\n", len, n_pkts, expected_len); - len -= 14; // we already read part of the index header - if(len<0) + if(len < 14) continue; + len -= 14; // we already read part of the index header goto skip; } else if (state == MKBETAG('D','A','T','A')) { av_log(s, AV_LOG_WARNING,