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: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2014-01-31 17:57:17 +01:00
parent 13aa82bbbb
commit 2884688bd5
4 changed files with 15 additions and 8 deletions

View File

@ -119,7 +119,7 @@ read_header:
8 * FFMIN(field_size, buf_end - buf_ptr - sos_offs)); 8 * FFMIN(field_size, buf_end - buf_ptr - sos_offs));
s->mjpb_skiptosod = (sod_offs - sos_offs - show_bits(&s->gb, 16)); s->mjpb_skiptosod = (sod_offs - sos_offs - show_bits(&s->gb, 16));
s->start_code = SOS; 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)) (avctx->err_recognition & AV_EF_EXPLODE))
return AVERROR_INVALIDDATA; return AVERROR_INVALIDDATA;
} }

View File

@ -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, static int mjpeg_decode_scan(MJpegDecodeContext *s, int nb_components, int Ah,
int Al, const uint8_t *mb_bitmask, int Al, const uint8_t *mb_bitmask,
int mb_bitmask_size,
const AVFrame *reference) const AVFrame *reference)
{ {
int i, mb_x, mb_y; 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; GetBitContext mb_bitmask_gb;
int bytes_per_pixel = 1 + (s->bits > 8); 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); init_get_bits(&mb_bitmask_gb, mb_bitmask, s->mb_width * s->mb_height);
}
s->restart_count = 0; 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, 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 len, nb_components, i, h, v, predictor, point_transform;
int index, id, ret; int index, id, ret;
@ -1397,7 +1403,7 @@ next_field:
} else { } else {
if ((ret = mjpeg_decode_scan(s, nb_components, if ((ret = mjpeg_decode_scan(s, nb_components,
prev_shift, point_transform, prev_shift, point_transform,
mb_bitmask, reference)) < 0) mb_bitmask, mb_bitmask_size, reference)) < 0)
return ret; return ret;
} }
} }
@ -1963,7 +1969,7 @@ eoi_parser:
goto the_end; goto the_end;
case SOS: case SOS:
s->cur_scan++; 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)) (avctx->err_recognition & AV_EF_EXPLODE))
goto fail; goto fail;
break; break;

View File

@ -137,7 +137,8 @@ int ff_mjpeg_decode_dqt(MJpegDecodeContext *s);
int ff_mjpeg_decode_dht(MJpegDecodeContext *s); int ff_mjpeg_decode_dht(MJpegDecodeContext *s);
int ff_mjpeg_decode_sof(MJpegDecodeContext *s); int ff_mjpeg_decode_sof(MJpegDecodeContext *s);
int ff_mjpeg_decode_sos(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, int ff_mjpeg_find_marker(MJpegDecodeContext *s,
const uint8_t **buf_ptr, const uint8_t *buf_end, const uint8_t **buf_ptr, const uint8_t *buf_end,
const uint8_t **unescaped_buf_ptr, int *unescaped_buf_size); const uint8_t **unescaped_buf_ptr, int *unescaped_buf_size);

View File

@ -295,11 +295,11 @@ static int mxpeg_decode_frame(AVCodecContext *avctx,
AV_GET_BUFFER_FLAG_REF)) < 0) AV_GET_BUFFER_FLAG_REF)) < 0)
return ret; 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)) if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
return ret; return ret;
} else { } 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)) if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
return ret; return ret;
} }