void oz_cdev_rx(struct oz_pd *pd, struct oz_elt *elt)
{
	struct oz_serial_ctx *ctx;
	struct oz_app_hdr *app_hdr;
	u8 *data;
	int len;
	int space;
	int copy_sz;
	int ix;

	ctx = oz_cdev_claim_ctx(pd);
	if (ctx == NULL) {
		oz_dbg(ON, "Cannot claim serial context\n");
		return;
	}

	app_hdr = (struct oz_app_hdr *)(elt+1);
	/* If sequence number is non-zero then check it is not a duplicate.
	 */
	if (app_hdr->elt_seq_num != 0) {
		if (((ctx->rx_seq_num - app_hdr->elt_seq_num) & 0x80) == 0) {
			/* Reject duplicate element. */
			oz_dbg(ON, "Duplicate element:%02x %02x\n",
			       app_hdr->elt_seq_num, ctx->rx_seq_num);
			goto out;
		}
	}
	ctx->rx_seq_num = app_hdr->elt_seq_num;
	len = elt->length - sizeof(struct oz_app_hdr);
	data = ((u8 *)(elt+1)) + sizeof(struct oz_app_hdr);
	if (len <= 0)
		goto out;
	space = ctx->rd_out - ctx->rd_in - 1;
	if (space < 0)
		space += OZ_RD_BUF_SZ;
	if (len > space) {
		oz_dbg(ON, "Not enough space:%d %d\n", len, space);
		len = space;
	}
	ix = ctx->rd_in;
	copy_sz = OZ_RD_BUF_SZ - ix;
	if (copy_sz > len)
		copy_sz = len;
	memcpy(&ctx->rd_buf[ix], data, copy_sz);
	len -= copy_sz;
	ix += copy_sz;
	if (ix == OZ_RD_BUF_SZ)
		ix = 0;
	if (len) {
		memcpy(ctx->rd_buf, data+copy_sz, len);
		ix = len;
	}
	ctx->rd_in = ix;
	wake_up(&g_cdev.rdq);
out:
	oz_cdev_release_ctx(ctx);
}

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.