From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id BEA8E47C9B for ; Wed, 18 Oct 2023 00:49:45 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 8CC6668C9FE; Wed, 18 Oct 2023 03:49:42 +0300 (EEST) Received: from relay3-d.mail.gandi.net (relay3-d.mail.gandi.net [217.70.183.195]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id BA1D36805B4 for ; Wed, 18 Oct 2023 03:49:36 +0300 (EEST) Received: by mail.gandi.net (Postfix) with ESMTPSA id E2FE660002 for ; Wed, 18 Oct 2023 00:49:35 +0000 (UTC) From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Wed, 18 Oct 2023 02:49:34 +0200 Message-Id: <20231018004935.18309-1-michael@niedermayer.cc> X-Mailer: git-send-email 2.17.1 X-Spam-Flag: yes X-Spam-Level: ************** X-GND-Spam-Score: 215 X-GND-Status: SPAM X-GND-Sasl: michael@niedermayer.cc Subject: [FFmpeg-devel] [PATCH 1/2] avformat/mxfdec: Check klv offset X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 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 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: Fixes: Assertion klv_offset >= mxf->run_in failed at libavformat/mxfdec.c:736 Fixes: 62936/clusterfuzz-testcase-minimized-ffmpeg_dem_MXF_fuzzer-5778404366221312.fuzz Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavformat/mxfdec.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c index 68939091e6..f2ec508b72 100644 --- a/libavformat/mxfdec.c +++ b/libavformat/mxfdec.c @@ -458,12 +458,15 @@ static int mxf_read_sync(AVIOContext *pb, const uint8_t *key, unsigned size) return i == size; } -static int klv_read_packet(KLVPacket *klv, AVIOContext *pb) +static int klv_read_packet(MXFContext *mxf, KLVPacket *klv, AVIOContext *pb) { int64_t length, pos; if (!mxf_read_sync(pb, mxf_klv_key, 4)) return AVERROR_INVALIDDATA; klv->offset = avio_tell(pb) - 4; + if (klv->offset < mxf->run_in) + return AVERROR_INVALIDDATA; + memcpy(klv->key, mxf_klv_key, 4); avio_read(pb, klv->key + 4, 12); length = klv_decode_ber_length(pb); @@ -3435,7 +3438,7 @@ static int mxf_seek_to_previous_partition(MXFContext *mxf) /* Make sure this is actually a PartitionPack, and if so parse it. * See deadlock2.mxf */ - if ((ret = klv_read_packet(&klv, pb)) < 0) { + if ((ret = klv_read_packet(mxf, &klv, pb)) < 0) { av_log(mxf->fc, AV_LOG_ERROR, "failed to read PartitionPack KLV\n"); return ret; } @@ -3712,7 +3715,7 @@ static void mxf_read_random_index_pack(AVFormatContext *s) if (length < min_rip_length || length > max_rip_length) goto end; avio_seek(s->pb, file_size - length, SEEK_SET); - if (klv_read_packet(&klv, s->pb) < 0 || + if (klv_read_packet(mxf, &klv, s->pb) < 0 || !IS_KLV_KEY(klv.key, ff_mxf_random_index_pack_key)) goto end; if (klv.next_klv != file_size || klv.length <= 4 || (klv.length - 4) % 12) { @@ -3759,7 +3762,7 @@ static int mxf_read_header(AVFormatContext *s) while (!avio_feof(s->pb)) { const MXFMetadataReadTableEntry *metadata; - ret = klv_read_packet(&klv, s->pb); + ret = klv_read_packet(mxf, &klv, s->pb); if (ret < 0 || IS_KLV_KEY(klv.key, ff_mxf_random_index_pack_key)) { if (ret >= 0 && avio_size(s->pb) > klv.next_klv) av_log(s, AV_LOG_WARNING, "data after the RandomIndexPack, assuming end of file\n"); @@ -4011,7 +4014,7 @@ static int mxf_read_packet(AVFormatContext *s, AVPacket *pkt) if (pos < mxf->current_klv_data.next_klv - mxf->current_klv_data.length || pos >= mxf->current_klv_data.next_klv) { mxf->current_klv_data = (KLVPacket){{0}}; - ret = klv_read_packet(&klv, s->pb); + ret = klv_read_packet(mxf, &klv, s->pb); if (ret < 0) break; max_data_size = klv.length; -- 2.17.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".