From patchwork Mon Feb 3 22:57:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 17683 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 194AA44AC99 for ; Tue, 4 Feb 2020 00:58:28 +0200 (EET) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 001ED689A59; Tue, 4 Feb 2020 00:58:27 +0200 (EET) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-dmta-pe02-3.mx.upcmail.net (vie01a-dmta-pe02-3.mx.upcmail.net [62.179.121.159]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 9C40E688135 for ; Tue, 4 Feb 2020 00:58:21 +0200 (EET) Received: from [172.31.216.235] (helo=vie01a-pemc-psmtp-pe12.mail.upcmail.net) by vie01a-dmta-pe02.mx.upcmail.net with esmtp (Exim 4.92) (envelope-from ) id 1iykfd-0009Vl-04 for ffmpeg-devel@ffmpeg.org; Mon, 03 Feb 2020 23:58:21 +0100 Received: from localhost ([213.47.68.29]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id ykeei1YyhwlysykeeiF5nD; Mon, 03 Feb 2020 23:57:21 +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=MKtGQD3n3ToA:10 a=1oJP67jkp3AA:10 a=GEAsPZ9sns4A:10 a=ZZnuYtJkoWoA:10 a=nZOtpAppAAAA:20 a=0MWZy_863otaIxLtkN4A:9 a=1fhp2MxaeJtTNGEnv6mo:22 a=Z5ABNNGmrOfJ6cZ5bIyy:22 a=UDnyf2zBuKT2w-IlGP_r:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Mon, 3 Feb 2020 23:57:20 +0100 Message-Id: <20200203225720.14324-1-michael@niedermayer.cc> X-Mailer: git-send-email 2.17.1 X-CMAE-Envelope: MS4wfAsNBLJOMWqICjdC7HOkrOtCnrYMlKDk5aniZ2LOiP9R306dbAbMjUEOao5Du4ifYSuI1CeMAxR0IdqihBBXAkZBz3DYevo8rJF5vFseSoD7Gfr68nqc LpMfys6Z2JopUptvjPM91CCIIEF3r8TtnteGgAIkQDRJwu1/MQQALa+3 Subject: [FFmpeg-devel] [PATCH] avcodec/flac_parser: Do not loose header count in find_headers_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 MIME-Version: 1.0 Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Fixes: Timeout Fixes: out of array access Fixes: 20274/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FLAC_fuzzer-5649631988154368 Fixes: 19275/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FLAC_fuzzer-5757535722405888 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/flac_parser.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/libavcodec/flac_parser.c b/libavcodec/flac_parser.c index 9ffa288548..3424583c49 100644 --- a/libavcodec/flac_parser.c +++ b/libavcodec/flac_parser.c @@ -208,16 +208,20 @@ static int find_headers_search(FLACParseContext *fpc, uint8_t *buf, uint32_t x; for (i = 0; i < mod_offset; i++) { - if ((AV_RB16(buf + i) & 0xFFFE) == 0xFFF8) - size = find_headers_search_validate(fpc, search_start + i); + if ((AV_RB16(buf + i) & 0xFFFE) == 0xFFF8) { + int ret = find_headers_search_validate(fpc, search_start + i); + size = FFMAX(size, ret); + } } for (; i < buf_size - 1; i += 4) { x = AV_RN32(buf + i); if (((x & ~(x + 0x01010101)) & 0x80808080)) { for (j = 0; j < 4; j++) { - if ((AV_RB16(buf + i + j) & 0xFFFE) == 0xFFF8) - size = find_headers_search_validate(fpc, search_start + i + j); + if ((AV_RB16(buf + i + j) & 0xFFFE) == 0xFFF8) { + int ret = find_headers_search_validate(fpc, search_start + i + j); + size = FFMAX(size, ret); + } } } }