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FFmpeg/libavcodec/vlc.h
Steinar H. Gunderson 08b098169b speedhq: fix out-of-bounds write
Certain alpha run lengths (for SHQ1/SHQ3/SHQ5) could be stored in
both long and short versions, and we would only accept the short version,
returning -1 (invalid code) for the others. This could cause an
out-of-bounds write on malicious input, as discovered by
Andreas Cadhalpun during fuzzing.

Fix by simply allowing both versions, leaving no invalid codes
in the alpha VLC.

Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
2017-02-02 01:12:07 +01:00

82 lines
3.3 KiB
C

/*
* 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
*/
#ifndef AVCODEC_VLC_H
#define AVCODEC_VLC_H
#include <stdint.h>
#define VLC_TYPE int16_t
typedef struct VLC {
int bits;
VLC_TYPE (*table)[2]; ///< code, bits
int table_size, table_allocated;
} VLC;
typedef struct RL_VLC_ELEM {
int16_t level;
int8_t len;
uint8_t run;
} RL_VLC_ELEM;
#define init_vlc(vlc, nb_bits, nb_codes, \
bits, bits_wrap, bits_size, \
codes, codes_wrap, codes_size, \
flags) \
ff_init_vlc_sparse(vlc, nb_bits, nb_codes, \
bits, bits_wrap, bits_size, \
codes, codes_wrap, codes_size, \
NULL, 0, 0, flags)
int ff_init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes,
const void *bits, int bits_wrap, int bits_size,
const void *codes, int codes_wrap, int codes_size,
const void *symbols, int symbols_wrap, int symbols_size,
int flags);
void ff_free_vlc(VLC *vlc);
#define INIT_VLC_LE 2
#define INIT_VLC_USE_NEW_STATIC 4
#define INIT_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, h, i, j, static_size) \
do { \
static VLC_TYPE table[static_size][2]; \
(vlc)->table = table; \
(vlc)->table_allocated = static_size; \
ff_init_vlc_sparse(vlc, bits, a, b, c, d, e, f, g, h, i, j, \
INIT_VLC_USE_NEW_STATIC); \
} while (0)
#define INIT_LE_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, h, i, j, static_size) \
do { \
static VLC_TYPE table[static_size][2]; \
(vlc)->table = table; \
(vlc)->table_allocated = static_size; \
ff_init_vlc_sparse(vlc, bits, a, b, c, d, e, f, g, h, i, j, \
INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE); \
} while (0)
#define INIT_VLC_STATIC(vlc, bits, a, b, c, d, e, f, g, static_size) \
INIT_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, NULL, 0, 0, static_size)
#define INIT_LE_VLC_STATIC(vlc, bits, a, b, c, d, e, f, g, static_size) \
INIT_LE_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, NULL, 0, 0, static_size)
#endif /* AVCODEC_VLC_H */