Commit 2884688b authored by Michael Niedermayer's avatar Michael Niedermayer

avcodec/mjpegdec: pass into ff_mjpeg_decode_sos() and check bitmask size

Fixes: heap array overread
Fixes: asan_heap-oob_149b2bc_6577_m1.mxg
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: 's avatarMichael Niedermayer <michaelni@gmx.at>
parent 13aa82bb
......@@ -119,7 +119,7 @@ read_header:
8 * FFMIN(field_size, buf_end - buf_ptr - sos_offs));
s->mjpb_skiptosod = (sod_offs - sos_offs - show_bits(&s->gb, 16));
s->start_code = SOS;
if (ff_mjpeg_decode_sos(s, NULL, NULL) < 0 &&
if (ff_mjpeg_decode_sos(s, NULL, 0, NULL) < 0 &&
(avctx->err_recognition & AV_EF_EXPLODE))
return AVERROR_INVALIDDATA;
}
......
......@@ -1100,6 +1100,7 @@ static void shift_output(MJpegDecodeContext *s, uint8_t *ptr, int linesize)
static int mjpeg_decode_scan(MJpegDecodeContext *s, int nb_components, int Ah,
int Al, const uint8_t *mb_bitmask,
int mb_bitmask_size,
const AVFrame *reference)
{
int i, mb_x, mb_y;
......@@ -1109,8 +1110,13 @@ static int mjpeg_decode_scan(MJpegDecodeContext *s, int nb_components, int Ah,
GetBitContext mb_bitmask_gb;
int bytes_per_pixel = 1 + (s->bits > 8);
if (mb_bitmask)
if (mb_bitmask) {
if (mb_bitmask_size != (s->mb_width * s->mb_height + 7)>>3) {
av_log(s->avctx, AV_LOG_ERROR, "mb_bitmask_size mismatches\n");
return AVERROR_INVALIDDATA;
}
init_get_bits(&mb_bitmask_gb, mb_bitmask, s->mb_width * s->mb_height);
}
s->restart_count = 0;
......@@ -1265,7 +1271,7 @@ static int mjpeg_decode_scan_progressive_ac(MJpegDecodeContext *s, int ss,
}
int ff_mjpeg_decode_sos(MJpegDecodeContext *s, const uint8_t *mb_bitmask,
const AVFrame *reference)
int mb_bitmask_size, const AVFrame *reference)
{
int len, nb_components, i, h, v, predictor, point_transform;
int index, id, ret;
......@@ -1397,7 +1403,7 @@ next_field:
} else {
if ((ret = mjpeg_decode_scan(s, nb_components,
prev_shift, point_transform,
mb_bitmask, reference)) < 0)
mb_bitmask, mb_bitmask_size, reference)) < 0)
return ret;
}
}
......@@ -1963,7 +1969,7 @@ eoi_parser:
goto the_end;
case SOS:
s->cur_scan++;
if ((ret = ff_mjpeg_decode_sos(s, NULL, NULL)) < 0 &&
if ((ret = ff_mjpeg_decode_sos(s, NULL, 0, NULL)) < 0 &&
(avctx->err_recognition & AV_EF_EXPLODE))
goto fail;
break;
......
......@@ -137,7 +137,8 @@ int ff_mjpeg_decode_dqt(MJpegDecodeContext *s);
int ff_mjpeg_decode_dht(MJpegDecodeContext *s);
int ff_mjpeg_decode_sof(MJpegDecodeContext *s);
int ff_mjpeg_decode_sos(MJpegDecodeContext *s,
const uint8_t *mb_bitmask, const AVFrame *reference);
const uint8_t *mb_bitmask,int mb_bitmask_size,
const AVFrame *reference);
int ff_mjpeg_find_marker(MJpegDecodeContext *s,
const uint8_t **buf_ptr, const uint8_t *buf_end,
const uint8_t **unescaped_buf_ptr, int *unescaped_buf_size);
......
......@@ -295,11 +295,11 @@ static int mxpeg_decode_frame(AVCodecContext *avctx,
AV_GET_BUFFER_FLAG_REF)) < 0)
return ret;
ret = ff_mjpeg_decode_sos(jpg, s->mxm_bitmask, reference_ptr);
ret = ff_mjpeg_decode_sos(jpg, s->mxm_bitmask, s->bitmask_size, reference_ptr);
if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
return ret;
} else {
ret = ff_mjpeg_decode_sos(jpg, NULL, NULL);
ret = ff_mjpeg_decode_sos(jpg, NULL, 0, NULL);
if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
return ret;
}
......
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