Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966372AbbBDWiq (ORCPT ); Wed, 4 Feb 2015 17:38:46 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:41782 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964917AbbBDWim (ORCPT ); Wed, 4 Feb 2015 17:38:42 -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 v3] PCI/sysfs: off by two when checking the limit on driver_override length Date: Wed, 4 Feb 2015 17:38:15 -0500 Message-Id: <1423089495-5647-1-git-send-email-sasha.levin@oracle.com> X-Mailer: git-send-email 2.1.0 X-Source-IP: acsinet21.oracle.com [141.146.126.237] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1732 Lines: 47 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 | 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/