From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:38385 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755047AbbAGUxP (ORCPT ); Wed, 7 Jan 2015 15:53:15 -0500 From: Sasha Levin To: linux-kernel@vger.kernel.org Cc: Sasha Levin , , Alex Williamson , Bjorn Helgaas , Konrad Rzeszutek Wilk , Alexander Graf , Greg Kroah-Hartman , linux-pci@vger.kernel.org (open list:PCI SUBSYSTEM) Subject: [PATCH v2] PCI/sysfs: off by two when checking the limit on driver_override length Date: Wed, 7 Jan 2015 15:52:57 -0500 Message-Id: <1420663977-30707-1-git-send-email-sasha.levin@oracle.com> Sender: linux-pci-owner@vger.kernel.org List-ID: 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 --- drivers/pci/pci-sysfs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index aa012fb..17459ed 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 >= (PATH_MAX - 1)) return -EINVAL; driver_override = kstrndup(buf, count, GFP_KERNEL); -- 1.7.10.4