Commit 108ca6fa authored by Anton Khirnov's avatar Anton Khirnov Committed by Reinhard Tartler

yop: check for input overreads.

CC:libav-stable@libav.org
(cherry picked from commit 8136f234)
Signed-off-by: 's avatarReinhard Tartler <siretart@tauware.de>
parent 7e35c50b
......@@ -39,6 +39,7 @@ typedef struct YopDecContext {
uint8_t *low_nibble;
uint8_t *srcptr;
uint8_t *src_end;
uint8_t *dstptr;
uint8_t *dstbuf;
} YopDecContext;
......@@ -123,8 +124,13 @@ static av_cold int yop_decode_close(AVCodecContext *avctx)
* @param s codec context
* @param tag the tag that was in the nibble
*/
static void yop_paint_block(YopDecContext *s, int tag)
static int yop_paint_block(YopDecContext *s, int tag)
{
if (s->src_end - s->srcptr < paint_lut[tag][3]) {
av_log(s->avctx, AV_LOG_ERROR, "Packet too small.\n");
return AVERROR_INVALIDDATA;
}
s->dstptr[0] = s->srcptr[0];
s->dstptr[1] = s->srcptr[paint_lut[tag][0]];
s->dstptr[s->frame.linesize[0]] = s->srcptr[paint_lut[tag][1]];
......@@ -132,6 +138,7 @@ static void yop_paint_block(YopDecContext *s, int tag)
// The number of src bytes consumed is in the last part of the lut entry.
s->srcptr += paint_lut[tag][3];
return 0;
}
/**
......@@ -185,6 +192,11 @@ static int yop_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
int ret, i, x, y;
uint32_t *palette;
if (avpkt->size < 4 + 3 * s->num_pal_colors) {
av_log(avctx, AV_LOG_ERROR, "Packet too small.\n");
return AVERROR_INVALIDDATA;
}
if (s->frame.data[0])
avctx->release_buffer(avctx, &s->frame);
......@@ -197,6 +209,7 @@ static int yop_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
s->dstbuf = s->frame.data[0];
s->dstptr = s->frame.data[0];
s->srcptr = avpkt->data + 4;
s->src_end = avpkt->data + avpkt->size;
s->low_nibble = NULL;
is_odd_frame = avpkt->data[0];
......@@ -220,7 +233,9 @@ static int yop_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
tag = yop_get_next_nibble(s);
if (tag != 0xf) {
yop_paint_block(s, tag);
ret = yop_paint_block(s, tag);
if (ret < 0)
return ret;
} else {
tag = yop_get_next_nibble(s);
ret = yop_copy_previous_block(s, tag);
......
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