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avcodec/mpeg4videodec: Check for bitstream end in read_quant_matrix_ext()

Fixes: out of array read
Fixes: asff-crash-0e53d0dc491dfdd507530b66562812fbd4c36678

Found-by: Paul Ch <paulcher@icloud.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2018-07-03 22:48:32 +02:00
parent e37741d26a
commit 5aba5b89d0

View File

@ -2867,11 +2867,13 @@ static int decode_vop_header(Mpeg4DecContext *ctx, GetBitContext *gb)
return 0;
}
static void read_quant_matrix_ext(MpegEncContext *s, GetBitContext *gb)
static int read_quant_matrix_ext(MpegEncContext *s, GetBitContext *gb)
{
int i, j, v;
if (get_bits1(gb)) {
if (get_bits_left(gb) < 64*8)
return AVERROR_INVALIDDATA;
/* intra_quantiser_matrix */
for (i = 0; i < 64; i++) {
v = get_bits(gb, 8);
@ -2882,6 +2884,8 @@ static void read_quant_matrix_ext(MpegEncContext *s, GetBitContext *gb)
}
if (get_bits1(gb)) {
if (get_bits_left(gb) < 64*8)
return AVERROR_INVALIDDATA;
/* non_intra_quantiser_matrix */
for (i = 0; i < 64; i++) {
get_bits(gb, 8);
@ -2889,6 +2893,8 @@ static void read_quant_matrix_ext(MpegEncContext *s, GetBitContext *gb)
}
if (get_bits1(gb)) {
if (get_bits_left(gb) < 64*8)
return AVERROR_INVALIDDATA;
/* chroma_intra_quantiser_matrix */
for (i = 0; i < 64; i++) {
v = get_bits(gb, 8);
@ -2898,6 +2904,8 @@ static void read_quant_matrix_ext(MpegEncContext *s, GetBitContext *gb)
}
if (get_bits1(gb)) {
if (get_bits_left(gb) < 64*8)
return AVERROR_INVALIDDATA;
/* chroma_non_intra_quantiser_matrix */
for (i = 0; i < 64; i++) {
get_bits(gb, 8);
@ -2905,6 +2913,7 @@ static void read_quant_matrix_ext(MpegEncContext *s, GetBitContext *gb)
}
next_start_code_studio(gb);
return 0;
}
static void extension_and_user_data(MpegEncContext *s, GetBitContext *gb, int id)