From patchwork Sun Dec 8 21:31:17 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 16674 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 3330C4487C8 for ; Sun, 8 Dec 2019 23:34:26 +0200 (EET) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 0D38F68B4B6; Sun, 8 Dec 2019 23:34:26 +0200 (EET) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-dmta-pe05-2.mx.upcmail.net (vie01a-dmta-pe05-2.mx.upcmail.net [84.116.36.12]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 81B3C68B03A for ; Sun, 8 Dec 2019 23:34:19 +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 1ie4C3-0006ea-18 for ffmpeg-devel@ffmpeg.org; Sun, 08 Dec 2019 22:34:19 +0100 Received: from localhost ([213.47.68.29]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id e4B5i75X8wlyse4B5i20rY; Sun, 08 Dec 2019 22:33:19 +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=E5OzWpVl c=1 sm=1 tr=0 a=2hcxjKEKjp0CzLx6oWAm4g==:117 a=2hcxjKEKjp0CzLx6oWAm4g==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=MKtGQD3n3ToA:10 a=1oJP67jkp3AA:10 a=GEAsPZ9sns4A:10 a=ZZnuYtJkoWoA:10 a=nZOtpAppAAAA:20 a=hVZu0dxsKLRBhoaT1QYA:9 a=1fhp2MxaeJtTNGEnv6mo:22 a=Z5ABNNGmrOfJ6cZ5bIyy:22 a=UDnyf2zBuKT2w-IlGP_r:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Sun, 8 Dec 2019 22:31:17 +0100 Message-Id: <20191208213120.15190-2-michael@niedermayer.cc> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191208213120.15190-1-michael@niedermayer.cc> References: <20191208213120.15190-1-michael@niedermayer.cc> MIME-Version: 1.0 X-CMAE-Envelope: MS4wfDE6f9aRpGrfmeFx5EFUea93Xokt+SLuAIMZGyTjziLk+2RQyquCCyu9VZ9lZRGlW8Zb5Obk7CV15GeiHtzbXBEBSfIF3iTRBr5QUudnlQQEpOo5vQzj MUT7ZL/8EEwBPgX+Oy2wVMuvUbj4fXvoCSm5gQ7C5KkU4Qrna+rGi/VC Subject: [FFmpeg-devel] [PATCH 2/5] avcodec/cbs_mpeg2: Change assertion from bytes to bits 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" This allows writing empty slices Fixes: Assertion slice->data_bit_start >= 0 && slice->data_size > slice->data_bit_start / 8 failed at libavcodec/cbs_mpeg2.c:340 Fixes: 19280/clusterfuzz-testcase-minimized-ffmpeg_BSF_MPEG2_METADATA_fuzzer-5632206173372416 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/cbs_mpeg2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavcodec/cbs_mpeg2.c b/libavcodec/cbs_mpeg2.c index 13d871cc89..b5286537db 100644 --- a/libavcodec/cbs_mpeg2.c +++ b/libavcodec/cbs_mpeg2.c @@ -337,7 +337,7 @@ static int cbs_mpeg2_write_slice(CodedBitstreamContext *ctx, uint8_t *pos = slice->data + slice->data_bit_start / 8; av_assert0(slice->data_bit_start >= 0 && - slice->data_size > slice->data_bit_start / 8); + slice->data_size * 8LL >= slice->data_bit_start); if (slice->data_size * 8 + 8 > put_bits_left(pbc)) return AVERROR(ENOSPC);