From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 44262C47083 for ; Mon, 31 May 2021 13:56:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3085161C91 for ; Mon, 31 May 2021 13:56:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232921AbhEaN6F (ORCPT ); Mon, 31 May 2021 09:58:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:60414 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230357AbhEaNzz (ORCPT ); Mon, 31 May 2021 09:55:55 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CC02860FE8; Mon, 31 May 2021 13:34:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1622468073; bh=PwlgtTkGS+1C9BvwQKkTVlLQQhHTBS25/lKjRtxMhC4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xZZ+H1hFOhPPusbi5rtHgRBuQa7kGGUW7CBQReCr/3KDC/JFuQbSiYVD1L0ZTWqsA hD16914Bdj389Jce/uQ6b0wIb6F0sl++9KRnpm/YmD/FVgmFP1BQ8cZIXolGNVcwRl NTFO1E0rVUJXNlFV2rBkiRHW1OVPr+3ps+lTcn4A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Linh Phung , Wolfram Sang , Ulrich Hecht , Geert Uytterhoeven Subject: [PATCH 5.10 079/252] serial: sh-sci: Fix off-by-one error in FIFO threshold register setting Date: Mon, 31 May 2021 15:12:24 +0200 Message-Id: <20210531130700.674221127@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210531130657.971257589@linuxfoundation.org> References: <20210531130657.971257589@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: stable@vger.kernel.org From: Geert Uytterhoeven commit 2ea2e019c190ee3973ef7bcaf829d8762e56e635 upstream. The Receive FIFO Data Count Trigger field (RTRG[6:0]) in the Receive FIFO Data Count Trigger Register (HSRTRGR) of HSCIF can only hold values ranging from 0-127. As the FIFO size is equal to 128 on HSCIF, the user can write an out-of-range value, touching reserved bits. Fix this by limiting the trigger value to the FIFO size minus one. Reverse the order of the checks, to avoid rx_trig becoming zero if the FIFO size is one. Note that this change has no impact on other SCIF variants, as their maximum supported trigger value is lower than the FIFO size anyway, and the code below takes care of enforcing these limits. Fixes: a380ed461f66d1b8 ("serial: sh-sci: implement FIFO threshold register setting") Reported-by: Linh Phung Reviewed-by: Wolfram Sang Reviewed-by: Ulrich Hecht Signed-off-by: Geert Uytterhoeven Cc: stable Link: https://lore.kernel.org/r/5eff320aef92ffb33d00e57979fd3603bbb4a70f.1620648218.git.geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sh-sci.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1023,10 +1023,10 @@ static int scif_set_rtrg(struct uart_por { unsigned int bits; + if (rx_trig >= port->fifosize) + rx_trig = port->fifosize - 1; if (rx_trig < 1) rx_trig = 1; - if (rx_trig >= port->fifosize) - rx_trig = port->fifosize; /* HSCIF can be set to an arbitrary level. */ if (sci_getreg(port, HSRTRGR)->size) {