static int ff_url_read(void *h, unsigned char *buf, int size)
{
	u32 retry = 10;
	u32 read;
	int full_size;
	FFDemux *ffd = (FFDemux *)h;

	full_size = 0;
	if (ffd->buffer_used) {
		if (ffd->buffer_used >= (u32) size) {
			ffd->buffer_used-=size;
			memcpy(ffd->buffer, ffd->buffer+size, sizeof(char)*ffd->buffer_used);
#ifdef FFMPEG_DUMP_REMOTE
			if (ffd->outdbg) gf_fwrite(buf, size, 1, ffd->outdbg);
#endif
			return size;
		}
		full_size += ffd->buffer_used;
		buf += ffd->buffer_used;
		size -= ffd->buffer_used;
		ffd->buffer_used = 0;
	}

	while (size) {
		GF_Err e = gf_dm_sess_fetch_data(ffd->dnload, buf, size, &read);
		if (e==GF_EOS) break;
		/*we're sync!!*/
		if (e==GF_IP_NETWORK_EMPTY) {
			if (!retry) {
				GF_LOG(GF_LOG_ERROR, GF_LOG_CONTAINER, ("[FFMPEG Demuxer] timeout fetching bytes from network\n") );
				return -1;
			}
			retry --;
			gf_sleep(100);
			continue;
		}
		if (e) {
			GF_LOG(GF_LOG_ERROR, GF_LOG_CONTAINER, ("[FFMPEG Demuxer] error fetching bytes from network: %s\n", gf_error_to_string(e) ) );
			return -1;
		}
		full_size += read;
		if (read==size) break;
		size -= read;
		buf += read;
	}
#ifdef FFMPEG_DUMP_REMOTE
	if (ffd->outdbg) gf_fwrite(ffd->buffer, full_size, 1, ffd->outdbg);
#endif
	return full_size ? (int) full_size : -1;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.