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=-9.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 680BFC433ED for ; Thu, 22 Apr 2021 16:50:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2BBBB613C3 for ; Thu, 22 Apr 2021 16:50:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238025AbhDVQvc (ORCPT ); Thu, 22 Apr 2021 12:51:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39686 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236236AbhDVQvc (ORCPT ); Thu, 22 Apr 2021 12:51:32 -0400 Received: from mail-pf1-x42b.google.com (mail-pf1-x42b.google.com [IPv6:2607:f8b0:4864:20::42b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C768C06174A; Thu, 22 Apr 2021 09:50:57 -0700 (PDT) Received: by mail-pf1-x42b.google.com with SMTP id c3so13328854pfo.3; Thu, 22 Apr 2021 09:50:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=5hy0qPxKAuOQZxRaS5noQvTTz10EqbX0MqSJa7kt2Pg=; b=FcD9yoy6RlcWqXUPhd2KTdTTLd0BHzIngJHPCtCuyxr1w5fFUVPUyCBxI0s50OUZ6/ WY8Hk9CifRaSKdJbpzJJ1slz4zi96tuJUIL7ykmGaUvr+eRmXDVetkWPS5jns05ZrqZM +s0UvyDKN1HAiqJfb5EI4ZHxa5N30wXdXFrPlRbispUt7NXbAfBr5uJCfTzcSh4huG1X 3HQvFvFze4AdKrfM8cG3QN3lsC7qx21qi2JQyj7QDQBAudhP0oKnj6nc8XcCS+U5RzlR dNYEiVrfctoKDDLMbeDlsqtRnG96F7e/Uj26VPSgLQ2D8RCrysJNbliO9VRSPf17A3sS QCTA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=5hy0qPxKAuOQZxRaS5noQvTTz10EqbX0MqSJa7kt2Pg=; b=LaIPbn3j1OubVOztHSuGRmNfijuCcmS1lL9nxu3fqOUCS7gxZtxFH526Ef03/TaxsF +hHzrwB0sKU4ecJat7WGZ5LPa5zboD800fpskdyhvA4wu34odF3eb993Wr7NaHRdcVB0 omEBixon0plP94gcKiNjepm1b/Ijat/Aha/qqIIeJrf3dYQMpWDy0ZtknQDiQTmkOczg aGzWPi6h525vG34lVVhqccxPZYvNRgGIYCnVvv4uqUzi9MvQBFW23c/QoUMqXbcHmLMM q96r6YUMQdLDmXQbyUUYk9dfGTVzSDLyJhR/MjPjk4s1kxMxEqVFxIbGq8CNeoR8jF4r FssQ== X-Gm-Message-State: AOAM5328Yl0cRIdhQcn0xAck6/kvkqk1xY8QSxURBN/LPg4F/r3vXUiR GsLddb0nGXxdMwh9NBh1+POytSjkZHQ= X-Google-Smtp-Source: ABdhPJxdJ60GHkYMKb5kIsdI6z/22Rx1Dprxev/IfzZZ0q0sXtjAPDEl/53ScSTDG9kabw9UYp4IYg== X-Received: by 2002:a63:6ec3:: with SMTP id j186mr4442123pgc.249.1619110256371; Thu, 22 Apr 2021 09:50:56 -0700 (PDT) Received: from [10.230.29.202] ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id w7sm2610642pff.208.2021.04.22.09.50.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 22 Apr 2021 09:50:55 -0700 (PDT) Subject: Re: [PATCH] spi: bcm2835: Fix buffer overflow with CS able to go beyond limit. To: Joe Burmeister , Mark Brown , Ray Jui , Scott Branden , bcm-kernel-feedback-list@broadcom.com, Nicolas Saenz Julienne , linux-spi@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20210420083402.6950-1-joe.burmeister@devtank.co.uk> From: Florian Fainelli Message-ID: Date: Thu, 22 Apr 2021 09:50:47 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.9.0 MIME-Version: 1.0 In-Reply-To: <20210420083402.6950-1-joe.burmeister@devtank.co.uk> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org On 4/20/2021 1:34 AM, Joe Burmeister wrote: > It was previoulsy possible to have a device tree with more chips than > the driver supports and go off the end of CS arrays. Do you mind walking me through the code how that could have happened? We have spi_register_controller() call of_spi_get_gpio_numbers() which has the following: ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect); such that what the controller has is the maximum between the number of 'cs-gpios' properties parsed and what was already populated in ctrl->num_chipselect during bcm2835_spi_probe(), which for this driver is BCM2835_SPI_NUM_CS (3). > > This patches inforces CS limit but sets that limit to the max of the > default limit and what is in the device tree when driver is loaded. > > Signed-off-by: Joe Burmeister You have changed many more things that just enforcing a limit on BCM2835_SPI_NUM_CS you have now made all chip-select related data structuresd dynamically allocated and you have changed a number of prints to use the shorthand "dev" instead of &pdev->dev. -- Florian