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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,URIBL_DBL_ABUSE_MALW, USER_AGENT_MUTT 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 426CDC433F4 for ; Mon, 24 Sep 2018 18:07:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA98021480 for ; Mon, 24 Sep 2018 18:06:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EA98021480 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org 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 S1732813AbeIYAKU (ORCPT ); Mon, 24 Sep 2018 20:10:20 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:54100 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726218AbeIYAKU (ORCPT ); Mon, 24 Sep 2018 20:10:20 -0400 Received: from localhost (ip-213-127-77-73.ip.prioritytelecom.net [213.127.77.73]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 5E480F06; Mon, 24 Sep 2018 18:06:57 +0000 (UTC) Date: Mon, 24 Sep 2018 20:06:54 +0200 From: Greg Kroah-Hartman To: Bartosz Golaszewski Cc: Linux Kernel Mailing List , stable , Linus Walleij , alexander.levin@microsoft.com Subject: Re: [PATCH 4.18 177/235] gpiolib: dont allow userspace to set values of input lines Message-ID: <20180924180654.GA31233@kroah.com> References: <20180924113103.999624566@linuxfoundation.org> <20180924113122.447077803@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 24, 2018 at 02:57:38PM +0200, Bartosz Golaszewski wrote: > pon., 24 wrz 2018 o 14:41 Greg Kroah-Hartman > napisał(a): > > > > 4.18-stable review patch. If anyone has any objections, please let me know. > > > > ------------------ > > > > From: Bartosz Golaszewski > > > > [ Upstream commit e5332d5437764f775cf4e3b8ca3bf592af063a02 ] > > > > 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 > > Signed-off-by: Linus Walleij > > Signed-off-by: Sasha Levin > > Signed-off-by: Greg Kroah-Hartman > > --- > > drivers/gpio/gpiolib.c | 8 +++++++- > > 1 file changed, 7 insertions(+), 1 deletion(-) > > > > --- a/drivers/gpio/gpiolib.c > > +++ b/drivers/gpio/gpiolib.c > > @@ -449,7 +449,13 @@ static long linehandle_ioctl(struct file > > > > 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; > > > > > > > > Hi Greg, > > FYI Linus suggested that we don't send this one for stable: > https://lkml.org/lkml/2018/7/20/1065 Ok, that was hard to dig out. This was sent as review last week. I'll go drop it, thanks for letting me know. greg k-h