matroska: Update the available size after lace parsing

Fix heap-buffer-overflow in matroska_parse_block for
corrupted real media in mkv files.

CC: libav-stable@libav.org

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
(cherry picked from commit fc43c19a56)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
This commit is contained in:
Dale Curtis
2013-03-27 14:02:03 -07:00
committed by Reinhard Tartler
parent 05015d03da
commit b90816d94b

View File

@@ -1757,10 +1757,10 @@ static void matroska_clear_queue(MatroskaDemuxContext *matroska)
} }
static int matroska_parse_laces(MatroskaDemuxContext *matroska, uint8_t **buf, static int matroska_parse_laces(MatroskaDemuxContext *matroska, uint8_t **buf,
int size, int type, int* buf_size, int type,
uint32_t **lace_buf, int *laces) uint32_t **lace_buf, int *laces)
{ {
int res = 0, n; int res = 0, n, size = *buf_size;
uint8_t *data = *buf; uint8_t *data = *buf;
uint32_t *lace_size; uint32_t *lace_size;
@@ -1858,6 +1858,7 @@ static int matroska_parse_laces(MatroskaDemuxContext *matroska, uint8_t **buf,
*buf = data; *buf = data;
*lace_buf = lace_size; *lace_buf = lace_size;
*buf_size = size;
return res; return res;
} }
@@ -2052,7 +2053,7 @@ static int matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data,
matroska->skip_to_keyframe = 0; matroska->skip_to_keyframe = 0;
} }
res = matroska_parse_laces(matroska, &data, size, (flags & 0x06) >> 1, res = matroska_parse_laces(matroska, &data, &size, (flags & 0x06) >> 1,
&lace_size, &laces); &lace_size, &laces);
if (res) if (res)