From patchwork Mon Jul 5 21:23:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= X-Patchwork-Id: 12359573 X-Patchwork-Delegate: bhelgaas@google.com 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 F10EAC07E99 for ; Mon, 5 Jul 2021 21:23:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D22EB6192B for ; Mon, 5 Jul 2021 21:23:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230015AbhGEVZv (ORCPT ); Mon, 5 Jul 2021 17:25:51 -0400 Received: from mail-lj1-f169.google.com ([209.85.208.169]:46716 "EHLO mail-lj1-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229987AbhGEVZt (ORCPT ); Mon, 5 Jul 2021 17:25:49 -0400 Received: by mail-lj1-f169.google.com with SMTP id q4so26240147ljp.13 for ; Mon, 05 Jul 2021 14:23:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=AAt2/9fsX8msYKcUtaCFzrmkaM3hAZjJLNAanXNK3v4=; b=rkPoKjeeTxIjiUX4kPexVyZUy7T1gbIA4VMcqPMllaRYF/TwviJlJba0fnopotlMmO UrXMT6OhCXPPO66zDVbGLvaNCeyW8HhlW+D6O9w/h5GwaEUvgSLW0pG7jjJBaCboB+7z gpnCfm5pZ2sEumKVEfVES0XK6VAh9YUt+1K2APd0JRgifCqjryxjvFUATg/tQ6FicYwd Iw414ujHi9IYLQYi9nbs6Lxv5aSzoMaKYH61ZydZTGKnUaFcwj1+c7ll5/bMMmsEvpEl Hm1IhAOC0YJ47J1kAqzp9D6QOgJgchoctbNVtZcGydTIJnn9pUdSsN71uu9rNDQtf0eo BDKQ== X-Gm-Message-State: AOAM530gKTt7DzStuOAFwMqqJoOqhhvYHrcge/poqUyY3NEIk1bLnx/I VGZgLhpoNBxI15ZAgM9CMmQ= X-Google-Smtp-Source: ABdhPJwS99HCdL/nZ/BNVCOLSY0qOHFoOMbg3oUVtlqH9dVz8vG6ZPkc9Ux7gR7cfPBdQtQJ/jzgLg== X-Received: by 2002:a05:651c:211f:: with SMTP id a31mr5572846ljq.216.1625520191265; Mon, 05 Jul 2021 14:23:11 -0700 (PDT) Received: from workstation.lan ([95.155.85.46]) by smtp.gmail.com with ESMTPSA id x1sm1191338lfa.21.2021.07.05.14.23.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Jul 2021 14:23:10 -0700 (PDT) From: =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= To: Bjorn Helgaas Cc: Lorenzo Pieralisi , Kishon Vijay Abraham I , linux-pci@vger.kernel.org Subject: [PATCH 2/4] PCI/sysfs: Check CAP_SYS_ADMIN before parsing user input Date: Mon, 5 Jul 2021 21:23:06 +0000 Message-Id: <20210705212308.3050976-2-kw@linux.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210705212308.3050976-1-kw@linux.com> References: <20210705212308.3050976-1-kw@linux.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Check if the "CAP_SYS_ADMIN" capability flag is set before parsing user input as it makes more sense to first check whether the current user actually has the right permissions before accepting any input from such user. This will also make order in which enable_store() and msi_bus_store() perform the "CAP_SYS_ADMIN" capability check consistent with other PCI-related sysfs objects that first verify whether user has this capability set. Signed-off-by: Krzysztof Wilczyński --- drivers/pci/pci-sysfs.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 0f98c4843764..bc4c141e4c1c 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -275,13 +275,13 @@ static ssize_t enable_store(struct device *dev, struct device_attribute *attr, struct pci_dev *pdev = to_pci_dev(dev); ssize_t result = 0; - if (kstrtobool(buf, &enable) < 0) - return -EINVAL; - /* this can crash the machine when done on the "wrong" device */ if (!capable(CAP_SYS_ADMIN)) return -EPERM; + if (kstrtobool(buf, &enable) < 0) + return -EINVAL; + device_lock(dev); if (dev->driver) result = -EBUSY; @@ -377,12 +377,12 @@ static ssize_t msi_bus_store(struct device *dev, struct device_attribute *attr, struct pci_dev *pdev = to_pci_dev(dev); struct pci_bus *subordinate = pdev->subordinate; - if (kstrtobool(buf, &enable) < 0) - return -EINVAL; - if (!capable(CAP_SYS_ADMIN)) return -EPERM; + if (kstrtobool(buf, &enable) < 0) + return -EINVAL; + /* * "no_msi" and "bus_flags" only affect what happens when a driver * requests MSI or MSI-X. They don't affect any drivers that have