1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-11-21 10:55:51 +02:00
FFmpeg/libavcodec/mscc.c
Michael Niedermayer e35fe3d8b9
avcodec/mscc & mwsc: Check loop counts before use
This could cause timeouts

Fixes: CID1439568 Untrusted loop bound

Sponsored-by: Sovereign Tech Fund
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2024-05-19 22:14:39 +02:00

286 lines
8.7 KiB
C

/*
* Mandsoft Screen Capture Codec decoder
*
* Copyright (c) 2017 Paul B Mahol
*
* 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 <stdio.h>
#include <string.h>
#include "libavutil/mem.h"
#include "avcodec.h"
#include "bytestream.h"
#include "codec_internal.h"
#include "decode.h"
#include "zlib_wrapper.h"
#include <zlib.h>
typedef struct MSCCContext {
unsigned bpp;
unsigned int decomp_size;
uint8_t *decomp_buf;
unsigned int uncomp_size;
uint8_t *uncomp_buf;
FFZStream zstream;
uint32_t pal[256];
} MSCCContext;
static int rle_uncompress(AVCodecContext *avctx, GetByteContext *gb, PutByteContext *pb)
{
MSCCContext *s = avctx->priv_data;
unsigned x = 0, y = 0;
while (bytestream2_get_bytes_left(gb) > 0) {
uint32_t fill;
int j;
unsigned run = bytestream2_get_byte(gb);
if (run) {
if (bytestream2_get_bytes_left_p(pb) < run * s->bpp)
return AVERROR_INVALIDDATA;
switch (avctx->bits_per_coded_sample) {
case 8:
fill = bytestream2_get_byte(gb);
break;
case 16:
fill = bytestream2_get_le16(gb);
break;
case 24:
fill = bytestream2_get_le24(gb);
break;
case 32:
fill = bytestream2_get_le32(gb);
break;
}
for (j = 0; j < run; j++) {
switch (avctx->bits_per_coded_sample) {
case 8:
bytestream2_put_byte(pb, fill);
break;
case 16:
bytestream2_put_le16(pb, fill);
break;
case 24:
bytestream2_put_le24(pb, fill);
break;
case 32:
bytestream2_put_le32(pb, fill);
break;
}
}
x += run;
} else {
unsigned copy = bytestream2_get_byte(gb);
if (copy == 0) {
x = 0;
y++;
bytestream2_seek_p(pb, y * avctx->width * s->bpp, SEEK_SET);
} else if (copy == 1) {
return 0;
} else if (copy == 2) {
x += bytestream2_get_byte(gb);
y += bytestream2_get_byte(gb);
bytestream2_seek_p(pb, y * avctx->width * s->bpp + x * s->bpp, SEEK_SET);
} else {
if (bytestream2_get_bytes_left_p(pb) < copy * s->bpp)
return AVERROR_INVALIDDATA;
for (j = 0; j < copy; j++) {
switch (avctx->bits_per_coded_sample) {
case 8:
bytestream2_put_byte(pb, bytestream2_get_byte(gb));
break;
case 16:
bytestream2_put_le16(pb, bytestream2_get_le16(gb));
break;
case 24:
bytestream2_put_le24(pb, bytestream2_get_le24(gb));
break;
case 32:
bytestream2_put_le32(pb, bytestream2_get_le32(gb));
break;
}
}
if (s->bpp == 1 && (copy & 1))
bytestream2_skip(gb, 1);
x += copy;
}
}
}
return AVERROR_INVALIDDATA;
}
static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
int *got_frame, AVPacket *avpkt)
{
MSCCContext *s = avctx->priv_data;
z_stream *const zstream = &s->zstream.zstream;
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
GetByteContext gb;
PutByteContext pb;
int ret, j;
if (avpkt->size < 3)
return buf_size;
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
if (avctx->pix_fmt == AV_PIX_FMT_PAL8) {
size_t size;
const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, &size);
if (pal && size == AVPALETTE_SIZE) {
#if FF_API_PALETTE_HAS_CHANGED
FF_DISABLE_DEPRECATION_WARNINGS
frame->palette_has_changed = 1;
FF_ENABLE_DEPRECATION_WARNINGS
#endif
for (j = 0; j < 256; j++)
s->pal[j] = 0xFF000000 | AV_RL32(pal + j * 4);
} else if (pal) {
av_log(avctx, AV_LOG_ERROR,
"Palette size %"SIZE_SPECIFIER" is wrong\n", size);
}
memcpy(frame->data[1], s->pal, AVPALETTE_SIZE);
}
ret = inflateReset(zstream);
if (ret != Z_OK) {
av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
return AVERROR_UNKNOWN;
}
zstream->next_out = s->decomp_buf;
zstream->avail_out = s->decomp_size;
if (avctx->codec_id == AV_CODEC_ID_MSCC) {
const uint8_t start = avpkt->data[2] ^ avpkt->data[0];
zstream->next_in = &start;
zstream->avail_in = 1;
ret = inflate(zstream, Z_NO_FLUSH);
if (ret != Z_OK || zstream->avail_in != 0)
goto inflate_error;
buf += 3;
buf_size -= 3;
}
zstream->next_in = buf;
zstream->avail_in = buf_size;
ret = inflate(zstream, Z_FINISH);
if (ret != Z_STREAM_END) {
inflate_error:
av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret);
return AVERROR_UNKNOWN;
}
bytestream2_init(&gb, s->decomp_buf, zstream->total_out);
bytestream2_init_writer(&pb, s->uncomp_buf, s->uncomp_size);
ret = rle_uncompress(avctx, &gb, &pb);
if (ret)
return ret;
for (j = 0; j < avctx->height; j++) {
memcpy(frame->data[0] + (avctx->height - j - 1) * frame->linesize[0],
s->uncomp_buf + s->bpp * j * avctx->width, s->bpp * avctx->width);
}
*got_frame = 1;
return avpkt->size;
}
static av_cold int decode_init(AVCodecContext *avctx)
{
MSCCContext *s = avctx->priv_data;
int stride;
switch (avctx->bits_per_coded_sample) {
case 8: avctx->pix_fmt = AV_PIX_FMT_PAL8; break;
case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555; break;
case 24: avctx->pix_fmt = AV_PIX_FMT_BGR24; break;
case 32: avctx->pix_fmt = AV_PIX_FMT_BGRA; break;
default:
av_log(avctx, AV_LOG_ERROR, "Unsupported bitdepth %i\n", avctx->bits_per_coded_sample);
return AVERROR_INVALIDDATA;
}
s->bpp = avctx->bits_per_coded_sample >> 3;
stride = 4 * ((avctx->width * avctx->bits_per_coded_sample + 31) / 32);
s->decomp_size = 2 * avctx->height * stride;
if (!(s->decomp_buf = av_malloc(s->decomp_size)))
return AVERROR(ENOMEM);
s->uncomp_size = avctx->height * stride;
if (!(s->uncomp_buf = av_malloc(s->uncomp_size)))
return AVERROR(ENOMEM);
return ff_inflate_init(&s->zstream, avctx);
}
static av_cold int decode_close(AVCodecContext *avctx)
{
MSCCContext *s = avctx->priv_data;
av_freep(&s->decomp_buf);
s->decomp_size = 0;
av_freep(&s->uncomp_buf);
s->uncomp_size = 0;
ff_inflate_end(&s->zstream);
return 0;
}
const FFCodec ff_mscc_decoder = {
.p.name = "mscc",
CODEC_LONG_NAME("Mandsoft Screen Capture Codec"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_MSCC,
.priv_data_size = sizeof(MSCCContext),
.init = decode_init,
.close = decode_close,
FF_CODEC_DECODE_CB(decode_frame),
.p.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
};
const FFCodec ff_srgc_decoder = {
.p.name = "srgc",
CODEC_LONG_NAME("Screen Recorder Gold Codec"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_SRGC,
.priv_data_size = sizeof(MSCCContext),
.init = decode_init,
.close = decode_close,
FF_CODEC_DECODE_CB(decode_frame),
.p.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
};