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=unavailable 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 ADF42C47083 for ; Mon, 31 May 2021 15:35:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E67B61263 for ; Mon, 31 May 2021 15:35:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233929AbhEaPgj (ORCPT ); Mon, 31 May 2021 11:36:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:48834 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233857AbhEaOVb (ORCPT ); Mon, 31 May 2021 10:21:31 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4A80C619C0; Mon, 31 May 2021 13:44:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1622468690; bh=zrSSD5pNPwNmFPdwAPPZmx+5i/cwBL/iK4acZnwDC+o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LIJLzyIm6RcJU803qeKdGnVqAfrIxmzcNhMUae/BqLnHxNUKekCLhwbjOYtzp79SH 415QygyoZxL7FISEaka0M0n93NfayqBY9JVIQr/2sOERvLpEOMqCqEKImPOp9YLCcV tv7hD6ys4HqfiAO/R20kWo8xda9TROH3XPbiUmaY= 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 5.4 054/177] serial: sh-sci: Fix off-by-one error in FIFO threshold register setting Date: Mon, 31 May 2021 15:13:31 +0200 Message-Id: <20210531130649.787362966@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210531130647.887605866@linuxfoundation.org> References: <20210531130647.887605866@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: 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 @@ -1026,10 +1026,10 @@ 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) {