From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966582AbdIYXuF (ORCPT ); Mon, 25 Sep 2017 19:50:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:55274 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966488AbdIYXuD (ORCPT ); Mon, 25 Sep 2017 19:50:03 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 218652148C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=helgaas@kernel.org Date: Mon, 25 Sep 2017 18:50:00 -0500 From: Bjorn Helgaas To: Nicolai Stange Cc: Bjorn Helgaas , Greg Kroah-Hartman , Adrian Salido , Sasha Levin , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH 3/3] driver core: platform: Don't read past the end of "driver_override" buffer Message-ID: <20170925235000.GI15970@bhelgaas-glaptop.roam.corp.google.com> References: <20170911074542.16777-1-nstange@suse.de> <20170911074542.16777-4-nstange@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170911074542.16777-4-nstange@suse.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Greg, I assume you'll deal with this one? Just let me know if I should do something with it. On Mon, Sep 11, 2017 at 09:45:42AM +0200, Nicolai Stange wrote: > When printing the driver_override parameter when it is 4095 and 4094 bytes > long, the printing code would access invalid memory because we need count+1 > bytes for printing. > > Reject driver_override values of these lengths in driver_override_store(). > > This is in close analogy to commit 4efe874aace5 ("PCI: Don't read past the > end of sysfs "driver_override" buffer") from Sasha Levin. > > Fixes: 3d713e0e382e ("driver core: platform: add device binding path 'driver_override'") > Cc: stable@vger.kernel.org # v3.17+ > Signed-off-by: Nicolai Stange > --- > drivers/base/platform.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > index d1bd99271066..9045c5f3734e 100644 > --- a/drivers/base/platform.c > +++ b/drivers/base/platform.c > @@ -868,7 +868,8 @@ static ssize_t driver_override_store(struct device *dev, > struct platform_device *pdev = to_platform_device(dev); > char *driver_override, *old, *cp; > > - if (count > PATH_MAX) > + /* We need to keep extra room for a newline */ > + if (count >= (PAGE_SIZE - 1)) > return -EINVAL; > > driver_override = kstrndup(buf, count, GFP_KERNEL); > -- > 2.13.5 >