From patchwork Wed Oct 28 22:56:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 23263 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 B0952448992 for ; Thu, 29 Oct 2020 00:57:50 +0200 (EET) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 9649268AD9D; Thu, 29 Oct 2020 00:57:50 +0200 (EET) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-dmta-pe05-1.mx.upcmail.net (vie01a-dmta-pe05-1.mx.upcmail.net [84.116.36.11]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 9A4D168A0FA for ; Thu, 29 Oct 2020 00:57:44 +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 1kXuO0-0004kL-0I for ffmpeg-devel@ffmpeg.org; Wed, 28 Oct 2020 23:57:44 +0100 Received: from localhost ([213.47.68.29]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id XuN2kAVVtIr7GXuN2kYZXt; Wed, 28 Oct 2020 23:56:44 +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=QN4WuTDL 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=1RWdHWJ_AAAA:8 a=1Z8TAvLxDYndi6kt5akA:9 a=Z6oB_PgadUjUZKMV:21 a=Ctj7Um3yZ6I04VGE:21 a=7CZ_-rfw-psA:10 a=tqavtLjfuPS5_DfqQoZn:22 a=pHzHmUro8NiASowvMSCR:22 a=n87TN5wuljxrRezIQYnT:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Wed, 28 Oct 2020 23:56:43 +0100 Message-Id: <20201028225643.30485-4-michael@niedermayer.cc> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201028225643.30485-1-michael@niedermayer.cc> References: <20201028225643.30485-1-michael@niedermayer.cc> X-CMAE-Envelope: MS4wfB4sfucuYFl7XPYK+6wCnU5YUOhp5X+SRs1MGIfXgdNz6TNfyDoy1u03UOEnsUa3Wjg9b02hrm42J5wGR194QqrDWOsBen0uJ6xVOt8qlcG4tftzarH3 D5Rk10DlcBRCekoVR0ZtSyQGfoR2xP07sROnu56j7Gdetb/xp8bzJ8jw Subject: [FFmpeg-devel] [PATCH 4/4] avformat/vividas: improve extradata packing checks in track_header() 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 accesses Fixes: 26622/clusterfuzz-testcase-minimized-ffmpeg_dem_VIVIDAS_fuzzer-6581200338288640 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavformat/vividas.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/libavformat/vividas.c b/libavformat/vividas.c index 7d59cd8fe9..08021c2752 100644 --- a/libavformat/vividas.c +++ b/libavformat/vividas.c @@ -28,6 +28,7 @@ * @sa http://wiki.multimedia.cx/index.php?title=Vividas_VIV */ +#include "libavutil/avassert.h" #include "libavutil/intreadwrite.h" #include "avio_internal.h" #include "avformat.h" @@ -376,7 +377,7 @@ static int track_header(VividasDemuxContext *viv, AVFormatContext *s, uint8_t * if (avio_tell(pb) < off) { int num_data; - int xd_size = 0; + int xd_size = 1; int data_len[256]; int offset = 1; uint8_t *p; @@ -390,10 +391,10 @@ static int track_header(VividasDemuxContext *viv, AVFormatContext *s, uint8_t * return AVERROR_INVALIDDATA; } data_len[j] = len; - xd_size += len; + xd_size += len + 1 + len/255; } - ret = ff_alloc_extradata(st->codecpar, 64 + xd_size + xd_size / 255); + ret = ff_alloc_extradata(st->codecpar, xd_size); if (ret < 0) return ret; @@ -402,9 +403,7 @@ static int track_header(VividasDemuxContext *viv, AVFormatContext *s, uint8_t * for (j = 0; j < num_data - 1; j++) { unsigned delta = av_xiphlacing(&p[offset], data_len[j]); - if (delta > data_len[j]) { - return AVERROR_INVALIDDATA; - } + av_assert0(delta <= xd_size - offset); offset += delta; } @@ -415,6 +414,7 @@ static int track_header(VividasDemuxContext *viv, AVFormatContext *s, uint8_t * av_freep(&st->codecpar->extradata); break; } + av_assert0(data_len[j] <= xd_size - offset); offset += data_len[j]; }