ffmpeg/libavformat/flac_picture.c
Andreas Rheinhardt 84a4261cd8 avformat/flac_picture: Switch to bytestream2 API
ff_flac_parse_picture() parses a buffer containing a flac metadata
picture block by wrapping it in an AVIOContext and using the AVIOContext
API. Consequently, when not enough data could be read AVERROR(EIO) was
returned although reading didn't really fail: A block that contains a
subfield whose size field indicates that it is so big as to extend
beyond the buffer is just invalid.

This commit changes this by using the bytestream2 API instead;
furthermore, the checks for whether there is enough data left are
performed before allocating a buffer for said data.

Finally, if the length of the picture description is bigger than
INT_MAX, it will now raise an error.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2019-12-01 17:17:04 +01:00

161 lines
5.0 KiB
C

/*
* Raw FLAC picture parser
* Copyright (c) 2001 Fabrice Bellard
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/intreadwrite.h"
#include "libavcodec/bytestream.h"
#include "libavcodec/png.h"
#include "avformat.h"
#include "flac_picture.h"
#include "id3v2.h"
#include "internal.h"
int ff_flac_parse_picture(AVFormatContext *s, uint8_t *buf, int buf_size)
{
const CodecMime *mime = ff_id3v2_mime_tags;
enum AVCodecID id = AV_CODEC_ID_NONE;
AVBufferRef *data = NULL;
uint8_t mimetype[64], *desc = NULL;
GetByteContext g;
AVStream *st;
int width, height, ret = 0;
unsigned int len, type;
if (buf_size < 34) {
av_log(s, AV_LOG_ERROR, "Attached picture metadata block too short\n");
if (s->error_recognition & AV_EF_EXPLODE)
return AVERROR_INVALIDDATA;
return 0;
}
bytestream2_init(&g, buf, buf_size);
/* read the picture type */
type = bytestream2_get_be32u(&g);
if (type >= FF_ARRAY_ELEMS(ff_id3v2_picture_types)) {
av_log(s, AV_LOG_ERROR, "Invalid picture type: %d.\n", type);
if (s->error_recognition & AV_EF_EXPLODE) {
RETURN_ERROR(AVERROR_INVALIDDATA);
}
type = 0;
}
/* picture mimetype */
len = bytestream2_get_be32u(&g);
if (len <= 0 || len >= sizeof(mimetype)) {
av_log(s, AV_LOG_ERROR, "Could not read mimetype from an attached "
"picture.\n");
if (s->error_recognition & AV_EF_EXPLODE)
ret = AVERROR_INVALIDDATA;
goto fail;
}
if (len + 24 > bytestream2_get_bytes_left(&g)) {
av_log(s, AV_LOG_ERROR, "Attached picture metadata block too short\n");
if (s->error_recognition & AV_EF_EXPLODE)
return AVERROR_INVALIDDATA;
return 0;
}
bytestream2_get_bufferu(&g, mimetype, len);
mimetype[len] = 0;
while (mime->id != AV_CODEC_ID_NONE) {
if (!strncmp(mime->str, mimetype, sizeof(mimetype))) {
id = mime->id;
break;
}
mime++;
}
if (id == AV_CODEC_ID_NONE) {
av_log(s, AV_LOG_ERROR, "Unknown attached picture mimetype: %s.\n",
mimetype);
if (s->error_recognition & AV_EF_EXPLODE)
ret = AVERROR_INVALIDDATA;
goto fail;
}
/* picture description */
len = bytestream2_get_be32u(&g);
if (len > bytestream2_get_bytes_left(&g) - 20) {
av_log(s, AV_LOG_ERROR, "Attached picture metadata block too short\n");
if (s->error_recognition & AV_EF_EXPLODE)
return AVERROR_INVALIDDATA;
return 0;
}
if (len > 0) {
if (!(desc = av_malloc(len + 1))) {
RETURN_ERROR(AVERROR(ENOMEM));
}
bytestream2_get_bufferu(&g, desc, len);
desc[len] = 0;
}
/* picture metadata */
width = bytestream2_get_be32u(&g);
height = bytestream2_get_be32u(&g);
bytestream2_skipu(&g, 8);
/* picture data */
len = bytestream2_get_be32u(&g);
if (len <= 0 || len > bytestream2_get_bytes_left(&g)) {
av_log(s, AV_LOG_ERROR, "Attached picture metadata block too short\n");
if (s->error_recognition & AV_EF_EXPLODE)
ret = AVERROR_INVALIDDATA;
goto fail;
}
if (!(data = av_buffer_alloc(len + AV_INPUT_BUFFER_PADDING_SIZE))) {
RETURN_ERROR(AVERROR(ENOMEM));
}
bytestream2_get_bufferu(&g, data->data, len);
memset(data->data + len, 0, AV_INPUT_BUFFER_PADDING_SIZE);
if (AV_RB64(data->data) == PNGSIG)
id = AV_CODEC_ID_PNG;
st = avformat_new_stream(s, NULL);
if (!st) {
RETURN_ERROR(AVERROR(ENOMEM));
}
av_init_packet(&st->attached_pic);
st->attached_pic.buf = data;
st->attached_pic.data = data->data;
st->attached_pic.size = len;
st->attached_pic.stream_index = st->index;
st->attached_pic.flags |= AV_PKT_FLAG_KEY;
st->disposition |= AV_DISPOSITION_ATTACHED_PIC;
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->codec_id = id;
st->codecpar->width = width;
st->codecpar->height = height;
av_dict_set(&st->metadata, "comment", ff_id3v2_picture_types[type], 0);
if (desc)
av_dict_set(&st->metadata, "title", desc, AV_DICT_DONT_STRDUP_VAL);
return 0;
fail:
av_buffer_unref(&data);
av_freep(&desc);
return ret;
}