From patchwork Sat Jan 23 22:10:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 25140 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 E725844887D for ; Sun, 24 Jan 2021 00:23:59 +0200 (EET) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id C0FF3689BDC; Sun, 24 Jan 2021 00:23:59 +0200 (EET) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-dmta-pe02-2.mx.upcmail.net (vie01a-dmta-pe02-2.mx.upcmail.net [62.179.121.158]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id AFE45680258 for ; Sun, 24 Jan 2021 00:23:52 +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 1l3R8Q-0003N8-0Q for ffmpeg-devel@ffmpeg.org; Sat, 23 Jan 2021 23:11:58 +0100 Received: from localhost ([213.47.68.29]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id 3R7Slm4hWO4rA3R7SlR7p7; Sat, 23 Jan 2021 23:10:58 +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=Qd-v1BCu9Pye61a_rOgA:9 a=1fhp2MxaeJtTNGEnv6mo:22 a=Z5ABNNGmrOfJ6cZ5bIyy:22 a=UDnyf2zBuKT2w-IlGP_r:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Sat, 23 Jan 2021 23:10:55 +0100 Message-Id: <20210123221056.3366-5-michael@niedermayer.cc> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210123221056.3366-1-michael@niedermayer.cc> References: <20210123221056.3366-1-michael@niedermayer.cc> X-CMAE-Envelope: MS4wfA98IJjU30Xu6KsFSCol/ae2o5V5zan3WiGR+2w7QOzOgE7PpCiNP+OhvlewrMzE1fEB/Samk+YSIX6h9t/mro59ZvKzHDDWFFzqV57ve8vcdDFG00io 2GyBxY/wkM14r4p8NMHXWgRREQmDvUxyri5BrcT07Z2mwflvuLGj1lP9 Subject: [FFmpeg-devel] [PATCH 5/6] avformat/flvdec: Check for nesting depth in amf_skip_tag() 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 access Fixes: 29440/clusterfuzz-testcase-minimized-ffmpeg_dem_KUX_fuzzer-5985279812960256.fuzz Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavformat/flvdec.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/libavformat/flvdec.c b/libavformat/flvdec.c index e15be0a221..4bc5e15dd2 100644 --- a/libavformat/flvdec.c +++ b/libavformat/flvdec.c @@ -842,10 +842,13 @@ static void clear_index_entries(AVFormatContext *s, int64_t pos) } } -static int amf_skip_tag(AVIOContext *pb, AMFDataType type) +static int amf_skip_tag(AVIOContext *pb, AMFDataType type, int depth) { int nb = -1, ret, parse_name = 1; + if (depth > MAX_DEPTH) + return AVERROR_PATCHWELCOME; + switch (type) { case AMF_DATA_TYPE_NUMBER: avio_skip(pb, 8); @@ -870,7 +873,7 @@ static int amf_skip_tag(AVIOContext *pb, AMFDataType type) } avio_skip(pb, size); } - if ((ret = amf_skip_tag(pb, avio_r8(pb))) < 0) + if ((ret = amf_skip_tag(pb, avio_r8(pb), depth + 1)) < 0) return ret; } break; @@ -914,7 +917,7 @@ static int flv_data_packet(AVFormatContext *s, AVPacket *pkt, else break; } else { - if ((ret = amf_skip_tag(pb, type)) < 0) + if ((ret = amf_skip_tag(pb, type, 0)) < 0) goto skip; } }