From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sasha Levin , Bjorn Helgaas , Alex Williamson , Konrad Rzeszutek Wilk , Alexander Graf Subject: [PATCH 3.19 093/123] PCI: Dont read past the end of sysfs "driver_override" buffer Date: Tue, 24 Mar 2015 16:46:42 +0100 Message-Id: <20150324154428.210875556@linuxfoundation.org> In-Reply-To: <20150324154423.655554012@linuxfoundation.org> References: <20150324154423.655554012@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sasha Levin commit 4efe874aace57dba967624ce1c48322da2447b75 upstream. 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. Fixes: 782a985d7af2 ("PCI: Introduce new device binding path using pci_dev.driver_override") Signed-off-by: Sasha Levin Signed-off-by: Bjorn Helgaas Acked-by: Alex Williamson CC: Konrad Rzeszutek Wilk CC: Alexander Graf CC: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pci-sysfs.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -521,7 +521,8 @@ static ssize_t driver_override_store(str 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(stru { 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);