avcodec/vmnc: Check location before use

Fixes: runtime error: signed integer overflow: 65535 * 64256 cannot be represented in type 'int'
Fixes: 1717/clusterfuzz-testcase-minimized-5491696676634624

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit ec2b76aab4)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2017-05-21 13:22:16 +02:00
parent ea4b807c0a
commit 5ceb27b0eb

View File

@ -374,6 +374,12 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
w = bytestream2_get_be16(gb);
h = bytestream2_get_be16(gb);
enc = bytestream2_get_be32(gb);
if ((dx + w > c->width) || (dy + h > c->height)) {
av_log(avctx, AV_LOG_ERROR,
"Incorrect frame size: %ix%i+%ix%i of %ix%i\n",
w, h, dx, dy, c->width, c->height);
return AVERROR_INVALIDDATA;
}
outptr = c->pic->data[0] + dx * c->bpp2 + dy * c->pic->linesize[0];
size_left = bytestream2_get_bytes_left(gb);
switch (enc) {
@ -451,12 +457,6 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
bytestream2_skip(gb, 2);
break;
case 0x00000000: // raw rectangle data
if ((dx + w > c->width) || (dy + h > c->height)) {
av_log(avctx, AV_LOG_ERROR,
"Incorrect frame size: %ix%i+%ix%i of %ix%i\n",
w, h, dx, dy, c->width, c->height);
return AVERROR_INVALIDDATA;
}
if (size_left < w * h * c->bpp2) {
av_log(avctx, AV_LOG_ERROR,
"Premature end of data! (need %i got %i)\n",
@ -467,12 +467,6 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
c->pic->linesize[0]);
break;
case 0x00000005: // HexTile encoded rectangle
if ((dx + w > c->width) || (dy + h > c->height)) {
av_log(avctx, AV_LOG_ERROR,
"Incorrect frame size: %ix%i+%ix%i of %ix%i\n",
w, h, dx, dy, c->width, c->height);
return AVERROR_INVALIDDATA;
}
res = decode_hextile(c, outptr, gb, w, h, c->pic->linesize[0]);
if (res < 0)
return res;