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=-2.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_MED, 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 987FEECDFAA for ; Mon, 16 Jul 2018 08:34:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 53A48208FE for ; Mon, 16 Jul 2018 08:34:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=bgdev-pl.20150623.gappssmtp.com header.i=@bgdev-pl.20150623.gappssmtp.com header.b="mL4UkTsj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 53A48208FE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bgdev.pl Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730810AbeGPJBD (ORCPT ); Mon, 16 Jul 2018 05:01:03 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:51952 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728129AbeGPJBC (ORCPT ); Mon, 16 Jul 2018 05:01:02 -0400 Received: by mail-wm0-f67.google.com with SMTP id s12-v6so14289318wmc.1 for ; Mon, 16 Jul 2018 01:34:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bgdev-pl.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=tTDn4uGQ0EwV3UUJYqVjoJWU273YjBzy6q3MKhVtuDM=; b=mL4UkTsjEjG4Jb85y4KvQjhfNtROuvH2DnpvsaRv86r7hAfmbstHHw9gpHV+GRGZWt Ug1Dseh70zlDZyUp2hFd7xTGO3geBgKqALZ5ye/lQzBdkAcjc/tHkxndxMB1x24cadlg qwsUXN3tmJFtUTAJdsyJGbcerdipb7H3oI7dIrk7PuVxQGGFUCi62WosKA7Nuv4Gr7y3 cWLOAPfmx+bvnCUv3Baixd8ZxxzrDndFyVR0ZlfBCp+ZyvO3wgYdArTtYF3yzPHFGNmA DU06KlQhlnshfRWFEXyIuDA7g2G91Wm4ONORS5n7N0nhAQgCPZfFGpHT4bdto5UAs+m4 16QA== 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; bh=tTDn4uGQ0EwV3UUJYqVjoJWU273YjBzy6q3MKhVtuDM=; b=qS20IqtwQUMcCfShTj4eMkxPAtXkvO6r8eEZx8K71DrKLB/2ZmK9iI3izcTWQc993y UhCwIe1mnWLfVebR2ho/B8D2dHlRF/RkKF02fOjoBdy3JXH2v+4gsMZFmaMN3kAhIxwf fINVzPDDkOUPO0WdowR8PJFcMBRuJrn0sXfquyiABIam2dhfcPM0URNUJLpO6mm2LYAp e9e6RxhB4ml/iACT3ZuQ0EtWVL72bwqlZ6tIAx8YPdWkwJf4castbMChGErUx727p/+G 4xh13xtF4LWx463DdCN/+a9OAspABLcl/PqJUcCzsaiz8iU4hRm9V5BcAcp9zd/WQJ0Q qyDw== X-Gm-Message-State: AOUpUlHUmLIu8vAeLH61qH8XmFJ8DBHFC9CKVl69n+C10VvqkgXV9ajg JSseXdQByzcNWdm9Tye11/0qlw== X-Google-Smtp-Source: AAOMgpeo5cRTF1MIT1q3h2a4Vca9Kh/qpxkUfdigYk/EvQ/VnYmKI4jx0vZGIA3odH5OpeUivtACWg== X-Received: by 2002:a1c:87ca:: with SMTP id j193-v6mr8980407wmd.76.1531730084314; Mon, 16 Jul 2018 01:34:44 -0700 (PDT) Received: from brgl-bgdev.home ([2a01:cb1d:af:5b00:e837:b8d5:48c1:571b]) by smtp.gmail.com with ESMTPSA id z3-v6sm29483104wru.27.2018.07.16.01.34.43 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 16 Jul 2018 01:34:43 -0700 (PDT) From: Bartosz Golaszewski To: Linus Walleij Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski Subject: [PATCH 1/2] gpiolib: don't allow userspace to set values of input lines Date: Mon, 16 Jul 2018 10:34:23 +0200 Message-Id: <20180716083424.11157-2-brgl@bgdev.pl> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180716083424.11157-1-brgl@bgdev.pl> References: <20180716083424.11157-1-brgl@bgdev.pl> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org User space can currently both read and set values of input lines using the character device. This was not allowed by the old sysfs interface nor is it a correct behavior. Check the first descriptor in the set for the OUT flag when asked to set values and return -EPERM if the line is input. Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index e11a3bb03820..57973524360d 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -449,7 +449,13 @@ static long linehandle_ioctl(struct file *filep, unsigned int cmd, return 0; } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) { - /* TODO: check if descriptors are really output */ + /* + * All line descriptors were created at once with the same + * flags so just check if the first one is really output. + */ + if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags)) + return -EPERM; + if (copy_from_user(&ghd, ip, sizeof(ghd))) return -EFAULT; -- 2.17.1