Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752945AbbBXXgK (ORCPT ); Tue, 24 Feb 2015 18:36:10 -0500 Received: from mail-ie0-f182.google.com ([209.85.223.182]:34030 "EHLO mail-ie0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752671AbbBXXgI (ORCPT ); Tue, 24 Feb 2015 18:36:08 -0500 Date: Tue, 24 Feb 2015 17:36:03 -0600 From: Bjorn Helgaas To: Sasha Levin Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Alex Williamson , Konrad Rzeszutek Wilk , Alexander Graf , Greg Kroah-Hartman , "open list:PCI SUBSYSTEM" Subject: Re: [PATCH v3] PCI/sysfs: off by two when checking the limit on driver_override length Message-ID: <20150224233603.GN6220@google.com> References: <1423089495-5647-1-git-send-email-sasha.levin@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1423089495-5647-1-git-send-email-sasha.levin@oracle.com> 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 Content-Length: 1934 Lines: 51 On Wed, Feb 04, 2015 at 05:38:15PM -0500, Sasha Levin 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. > > Cc: # v3.16+ > Fixes: 782a985d ("PCI: Introduce new device binding path using pci_dev.driver_override") > Cc: Alex Williamson > Cc: Bjorn Helgaas > Cc: Konrad Rzeszutek Wilk > Cc: Alexander Graf > Cc: Greg Kroah-Hartman > Signed-off-by: Sasha Levin Applied with Alex's ack to for-linus for v4.0, thanks! > --- > drivers/pci/pci-sysfs.c | 5 +++-- > 1 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c > index aa012fb..312f23a 100644 > --- a/drivers/pci/pci-sysfs.c > +++ b/drivers/pci/pci-sysfs.c > @@ -521,7 +521,8 @@ static ssize_t driver_override_store(struct device *dev, > struct pci_dev *pdev = to_pci_dev(dev); > char *driver_override, *old = pdev->driver_override, *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); > @@ -549,7 +550,7 @@ static ssize_t driver_override_show(struct device *dev, > { > struct pci_dev *pdev = to_pci_dev(dev); > > - return sprintf(buf, "%s\n", pdev->driver_override); > + return snprintf(buf, PAGE_SIZE, "%s\n", pdev->driver_override); > } > static DEVICE_ATTR_RW(driver_override); > > -- > 1.7.10.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/