From patchwork Tue Jan 12 21:51:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 24933 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 8577B44A282 for ; Tue, 12 Jan 2021 23:58:14 +0200 (EET) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 6DC1568ACEC; Tue, 12 Jan 2021 23:58:14 +0200 (EET) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-dmta-pe05-3.mx.upcmail.net (vie01a-dmta-pe05-3.mx.upcmail.net [84.116.36.13]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id E2EC668ACAB for ; Tue, 12 Jan 2021 23:58:07 +0200 (EET) Received: from [172.31.216.235] (helo=vie01a-pemc-psmtp-pe12.mail.upcmail.net) by vie01a-dmta-pe05.mx.upcmail.net with esmtp (Exim 4.92) (envelope-from ) id 1kzRaL-00072v-0G for ffmpeg-devel@ffmpeg.org; Tue, 12 Jan 2021 22:52:17 +0100 Received: from localhost ([213.47.68.29]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id zRZMkQEN3O4rAzRZMkasEb; Tue, 12 Jan 2021 22:51:17 +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=Rak3_ihYEDlvPqPQaisA:9 a=1fhp2MxaeJtTNGEnv6mo:22 a=Z5ABNNGmrOfJ6cZ5bIyy:22 a=UDnyf2zBuKT2w-IlGP_r:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Tue, 12 Jan 2021 22:51:13 +0100 Message-Id: <20210112215116.21186-1-michael@niedermayer.cc> X-Mailer: git-send-email 2.17.1 X-CMAE-Envelope: MS4wfCka9TSc+bF10baA8YzVi5/BoO/QEapdUfW2d/UldK9jA7YHbBM2RUK8IVynnLEQw2ikCN5TpLNaUGN0Rb/rarZJX244x+AessIL3HJGOMkvXDMV/dao FJXXhqjn6QjgEatIPbiWHzRgn00+meXBEwkghgONfE6eNtWT9SiFrR7p Subject: [FFmpeg-devel] [PATCH 1/4] avformat/asfdec_o: Check size vs. offset in detect_unknown_subobject() 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: 2314885530818453566 + 7503032301549264928 cannot be represented in type 'long' Fixes: 26639/clusterfuzz-testcase-minimized-ffmpeg_dem_ASF_O_fuzzer-6024222100684800 Alternatively this could be ignored but then the end condition of the loop would be hard to reach as avio_tell() is int64_t Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavformat/asfdec_o.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/libavformat/asfdec_o.c b/libavformat/asfdec_o.c index 655ba9f9ef..6ce5a3fb43 100644 --- a/libavformat/asfdec_o.c +++ b/libavformat/asfdec_o.c @@ -1661,6 +1661,9 @@ static int detect_unknown_subobject(AVFormatContext *s, int64_t offset, int64_t ff_asf_guid guid; int ret; + if (offset > INT64_MAX - size) + return AVERROR_INVALIDDATA; + while (avio_tell(pb) <= offset + size) { if (avio_tell(pb) == asf->offset) break;