Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3E76AC433FE for ; Mon, 3 Jan 2022 14:23:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232410AbiACOXq (ORCPT ); Mon, 3 Jan 2022 09:23:46 -0500 Received: from sin.source.kernel.org ([145.40.73.55]:45848 "EHLO sin.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233459AbiACOWo (ORCPT ); Mon, 3 Jan 2022 09:22:44 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id BBA62CE1106; Mon, 3 Jan 2022 14:22:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D429C36AED; Mon, 3 Jan 2022 14:22:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1641219761; bh=+Kb/GSarWuzEcaHbAJdggvzoiCNmLN17aKPiF3KKphA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Uc7OJSXHSfz4QuLjsXx0UbnGKCMMdI68AZcKMs7JZaEymB/qwVom5v78aK41yM6cJ ujO/u1U/3T26Wj2oUDXAhjnpsm+ZD3p+MkSHWBLrwwSZlZ0QLu38ksKtAIvYoCqPOA OEqnuWoMhueKxzasQC+ZvbBcAkasCOvnr2iZVaZw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Leo L. Schwab" , Dmitry Torokhov Subject: [PATCH 4.9 12/13] Input: spaceball - fix parsing of movement data packets Date: Mon, 3 Jan 2022 15:21:28 +0100 Message-Id: <20220103142052.351190921@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220103142051.979780231@linuxfoundation.org> References: <20220103142051.979780231@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Leo L. Schwab commit bc7ec91718c49d938849697cfad98fcd9877cc26 upstream. The spaceball.c module was not properly parsing the movement reports coming from the device. The code read axis data as signed 16-bit little-endian values starting at offset 2. In fact, axis data in Spaceball movement reports are signed 16-bit big-endian values starting at offset 3. This was determined first by visually inspecting the data packets, and later verified by consulting: http://spacemice.org/pdf/SpaceBall_2003-3003_Protocol.pdf If this ever worked properly, it was in the time before Git... Signed-off-by: Leo L. Schwab Link: https://lore.kernel.org/r/20211221101630.1146385-1-ewhac@ewhac.org Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman --- drivers/input/joystick/spaceball.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/drivers/input/joystick/spaceball.c +++ b/drivers/input/joystick/spaceball.c @@ -35,6 +35,7 @@ #include #include #include +#include #define DRIVER_DESC "SpaceTec SpaceBall 2003/3003/4000 FLX driver" @@ -91,9 +92,15 @@ static void spaceball_process_packet(str case 'D': /* Ball data */ if (spaceball->idx != 15) return; - for (i = 0; i < 6; i++) + /* + * Skip first three bytes; read six axes worth of data. + * Axis values are signed 16-bit big-endian. + */ + data += 3; + for (i = 0; i < ARRAY_SIZE(spaceball_axes); i++) { input_report_abs(dev, spaceball_axes[i], - (__s16)((data[2 * i + 3] << 8) | data[2 * i + 2])); + (__s16)get_unaligned_be16(&data[i * 2])); + } break; case 'K': /* Button data */