bmv: add stricter checks for invalid decoded length

This makes decoder handle random data passed as BMV frame data.
This commit is contained in:
Kostya Shishkov 2012-06-01 20:51:57 +02:00
parent cf3a1948e9
commit 96fadfb158

View File

@ -52,7 +52,7 @@ typedef struct BMVDecContext {
static int decode_bmv_frame(const uint8_t *source, int src_len, uint8_t *frame, int frame_off)
{
int val, saved_val = 0;
unsigned val, saved_val = 0;
int tmplen = src_len;
const uint8_t *src, *source_end = source + src_len;
uint8_t *frame_end = frame + SCREEN_WIDE * SCREEN_HIGH;
@ -140,7 +140,9 @@ static int decode_bmv_frame(const uint8_t *source, int src_len, uint8_t *frame,
case 1:
if (forward) {
if (dst - frame + SCREEN_WIDE < frame_off ||
frame_end - dst < frame_off + len)
dst - frame + SCREEN_WIDE + frame_off < 0 ||
frame_end - dst < frame_off + len ||
frame_end - dst < len)
return -1;
for (i = 0; i < len; i++)
dst[i] = dst[frame_off + i];
@ -148,7 +150,9 @@ static int decode_bmv_frame(const uint8_t *source, int src_len, uint8_t *frame,
} else {
dst -= len;
if (dst - frame + SCREEN_WIDE < frame_off ||
frame_end - dst < frame_off + len)
dst - frame + SCREEN_WIDE + frame_off < 0 ||
frame_end - dst < frame_off + len ||
frame_end - dst < len)
return -1;
for (i = len - 1; i >= 0; i--)
dst[i] = dst[frame_off + i];