From patchwork Sun Jan 31 21:56:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 25306 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 1178E44BA7A for ; Sun, 31 Jan 2021 23:57:14 +0200 (EET) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id EE843689C64; Sun, 31 Jan 2021 23:57:13 +0200 (EET) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-dmta-pe03-2.mx.upcmail.net (vie01a-dmta-pe03-2.mx.upcmail.net [62.179.121.161]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 0A6B8680064 for ; Sun, 31 Jan 2021 23:57:06 +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 1l6KiP-0001tm-09 for ffmpeg-devel@ffmpeg.org; Sun, 31 Jan 2021 22:57:05 +0100 Received: from localhost ([213.47.68.29]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id 6KhRliaQtO4rA6KhRlhywG; Sun, 31 Jan 2021 22:56:05 +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=uzEbCg_Xn-TzDeM9lTYA:9 a=1fhp2MxaeJtTNGEnv6mo:22 a=Z5ABNNGmrOfJ6cZ5bIyy:22 a=UDnyf2zBuKT2w-IlGP_r:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Sun, 31 Jan 2021 22:56:02 +0100 Message-Id: <20210131215605.28190-2-michael@niedermayer.cc> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210131215605.28190-1-michael@niedermayer.cc> References: <20210131215605.28190-1-michael@niedermayer.cc> X-CMAE-Envelope: MS4wfGbVt94Xpewq56SiZntvVIWizuJcbzfSg2tJClyp62wmnyb4J4lEBlwDrr0tGcVzTinDhO7tlZeJflcveVj+tFRNQabyBbn1JiLfq2BHJydVSzvTVYdN DEtvxyhDYf0DNgZ2iMFn4N2bEkngWe9elGyWXf5Xo7tTV7evq7fU5m5p Subject: [FFmpeg-devel] [PATCH 2/5] avcodec/ffv1dec: Check if trailer is available 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: out of array read Fixes: 29750/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FFV1_fuzzer-4808377272238080.fuzz Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/ffv1dec.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/libavcodec/ffv1dec.c b/libavcodec/ffv1dec.c index 0a3f425493..8516fef5d7 100644 --- a/libavcodec/ffv1dec.c +++ b/libavcodec/ffv1dec.c @@ -888,8 +888,10 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPac int trailer = 3 + 5*!!f->ec; int v; - if (i || f->version > 2) v = AV_RB24(buf_p-trailer) + trailer; - else v = buf_p - c->bytestream_start; + if (i || f->version > 2) { + if (trailer > buf_p - buf) v = INT_MAX; + else v = AV_RB24(buf_p-trailer) + trailer; + } else v = buf_p - c->bytestream_start; if (buf_p - c->bytestream_start < v) { av_log(avctx, AV_LOG_ERROR, "Slice pointer chain broken\n"); ff_thread_report_progress(&f->picture, INT_MAX, 0);