From patchwork Wed Jan 9 00:01:20 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 11683 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 166FE44D85F for ; Wed, 9 Jan 2019 02:02:44 +0200 (EET) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id B695A68A647; Wed, 9 Jan 2019 02:02:40 +0200 (EET) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-qmta-pe02-3.mx.upcmail.net (vie01a-qmta-pe02-3.mx.upcmail.net [62.179.121.183]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id E426868A57B for ; Wed, 9 Jan 2019 02:02:33 +0200 (EET) Received: from [172.31.218.46] (helo=vie01a-dmta-pe06-1.mx.upcmail.net) by vie01a-pqmta-pe02.mx.upcmail.net with esmtp (Exim 4.88) (envelope-from ) id 1gh1KX-0000ui-1o for ffmpeg-devel@ffmpeg.org; Wed, 09 Jan 2019 01:02:45 +0100 Received: from [172.31.216.235] (helo=vie01a-pemc-psmtp-pe12.mail.upcmail.net) by vie01a-dmta-pe06.mx.upcmail.net with esmtp (Exim 4.88) (envelope-from ) id 1gh1KR-0007HH-0c for ffmpeg-devel@ffmpeg.org; Wed, 09 Jan 2019 01:02:39 +0100 Received: from localhost ([213.47.41.20]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id h1JTgwCBd2WSsh1JTgufZB; Wed, 09 Jan 2019 01:01:39 +0100 X-Env-Mailfrom: michael@niedermayer.cc X-Env-Rcptto: ffmpeg-devel@ffmpeg.org X-SourceIP: 213.47.41.20 X-CNFS-Analysis: v=2.3 cv=E7kcWpVl c=1 sm=1 tr=0 a=I1eytVlZLDX1BM2VTtTtSw==:117 a=I1eytVlZLDX1BM2VTtTtSw==:17 a=MKtGQD3n3ToA:10 a=1oJP67jkp3AA:10 a=GEAsPZ9sns4A:10 a=ZZnuYtJkoWoA:10 a=nZOtpAppAAAA:20 a=pEOrThesvCKPq1nD9s8A:9 a=pHzHmUro8NiASowvMSCR:22 a=nt3jZW36AmriUCFCBwmW:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Wed, 9 Jan 2019 01:01:20 +0100 Message-Id: <20190109000122.17610-1-michael@niedermayer.cc> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-CMAE-Envelope: MS4wfIVo8twn9Fi69Ct6GfinyDvnagbsKjreqO16Tia4Anh7UBPs5DMvb7/lk2qPr+5INms6EC+INhj8Jtrq9LLGXNJkAHWfH8NwbHbkDPCE8FbQWRlKiBVA avgP2MYUHZaMd3xqDMaHms/o1hJcK++j5MUPGDdUOstTd6L3QLnYUzNZ Subject: [FFmpeg-devel] [PATCH 1/3] avcodec/ac3dec: Optimize frame start search 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" Fixes: Timeout Fixes: 11619/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AC3_FIXED_fuzzer-5632398021099520 Fixes: 11620/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AC3_fuzzer-5711996515778560 Fixes: 11658/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_EAC3_fuzzer-5701006524940288 Before: Executed clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AC3_FIXED_fuzzer-5632398021099520 in 20338 ms After: Executed clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AC3_FIXED_fuzzer-5632398021099520 in 11825 ms Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/ac3dec.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c index ba731314b4..1e89ba9ce2 100644 --- a/libavcodec/ac3dec.c +++ b/libavcodec/ac3dec.c @@ -1467,6 +1467,7 @@ static int ac3_decode_frame(AVCodecContext * avctx, void *data, int buf_size, full_buf_size = avpkt->size; AC3DecodeContext *s = avctx->priv_data; int blk, ch, err, offset, ret; + int i; int skip = 0, got_independent_frame = 0; const uint8_t *channel_map; uint8_t extended_channel_map[EAC3_MAX_CHANNELS]; @@ -1477,14 +1478,21 @@ static int ac3_decode_frame(AVCodecContext * avctx, void *data, s->superframe_size = 0; buf_size = full_buf_size; - while (buf_size > 2) { - if (AV_RB16(buf) != 0x770B && AV_RL16(buf) != 0x770B) { - buf += 1; - buf_size -= 1; - continue; + for (i= 1; i= buf_size) + return AVERROR_INVALIDDATA; + buf += i; + buf_size -= i; + /* copy input buffer to decoder context to avoid reading past the end of the buffer, which can be caused by a damaged input stream. */ if (buf_size >= 2 && AV_RB16(buf) == 0x770B) {