fraps: Make the input buffer size checks more strict

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
Signed-off-by: Martin Storsjö <martin@martin.st>
This commit is contained in:
Martin Storsjö 2013-09-19 16:29:23 +03:00
parent 82e266c6d3
commit 3185a80259
1 changed files with 19 additions and 11 deletions

View File

@ -145,10 +145,17 @@ static int decode_frame(AVCodecContext *avctx,
uint32_t offs[4];
int i, j, ret, is_chroma, planes;
enum AVPixelFormat pix_fmt;
int prev_pic_bit, expected_size;
if (buf_size < 4) {
av_log(avctx, AV_LOG_ERROR, "Packet is too short\n");
return AVERROR_INVALIDDATA;
}
header = AV_RL32(buf);
version = header & 0xff;
header_size = (header & (1<<30))? 8 : 4; /* bit 30 means pad to 8 bytes */
prev_pic_bit = header & (1U << 31); /* bit 31 means same as previous pic */
if (version > 5) {
av_log(avctx, AV_LOG_ERROR,
@ -167,16 +174,18 @@ static int decode_frame(AVCodecContext *avctx,
}
avctx->pix_fmt = pix_fmt;
expected_size = header_size;
switch (version) {
case 0:
default:
/* Fraps v0 is a reordered YUV420 */
if ((buf_size != avctx->width * avctx->height * 3 / 2 + header_size) &&
(buf_size != header_size)) {
if (!prev_pic_bit)
expected_size += avctx->width * avctx->height * 3 / 2;
if (buf_size != expected_size) {
av_log(avctx, AV_LOG_ERROR,
"Invalid frame length %d (should be %d)\n",
buf_size,
avctx->width * avctx->height * 3 / 2 + header_size);
buf_size, expected_size);
return AVERROR_INVALIDDATA;
}
@ -190,8 +199,7 @@ static int decode_frame(AVCodecContext *avctx,
av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
return ret;
}
/* bit 31 means same as previous pic */
f->pict_type = (header & (1U << 31)) ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
f->pict_type = prev_pic_bit ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
f->key_frame = f->pict_type == AV_PICTURE_TYPE_I;
if (f->pict_type == AV_PICTURE_TYPE_I) {
@ -215,11 +223,12 @@ static int decode_frame(AVCodecContext *avctx,
case 1:
/* Fraps v1 is an upside-down BGR24 */
if ((buf_size != avctx->width * avctx->height * 3 + header_size) &&
(buf_size != header_size) ) {
if (!prev_pic_bit)
expected_size += avctx->width * avctx->height * 3;
if (buf_size != expected_size) {
av_log(avctx, AV_LOG_ERROR,
"Invalid frame length %d (should be %d)\n",
buf_size, avctx->width * avctx->height * 3 + header_size);
buf_size, expected_size);
return AVERROR_INVALIDDATA;
}
@ -227,8 +236,7 @@ static int decode_frame(AVCodecContext *avctx,
av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
return ret;
}
/* bit 31 means same as previous pic */
f->pict_type = (header & (1U<<31))? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
f->pict_type = prev_pic_bit ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
f->key_frame = f->pict_type == AV_PICTURE_TYPE_I;
if (f->pict_type == AV_PICTURE_TYPE_I) {