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authorSasha Levin <sasha.levin@oracle.com>2015-02-04 23:38:15 +0100
committerBjorn Helgaas <bhelgaas@google.com>2015-02-25 00:35:37 +0100
commit4efe874aace57dba967624ce1c48322da2447b75 (patch)
treeba383d9fc961261e699a239fd213d467c1a5bbc8
parentLinux 4.0-rc1 (diff)
downloadlinux-4efe874aace57dba967624ce1c48322da2447b75.tar.xz
linux-4efe874aace57dba967624ce1c48322da2447b75.zip
PCI: Don't read past the end of sysfs "driver_override" buffer
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 <sasha.levin@oracle.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> CC: stable@vger.kernel.org # v3.16+ CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> CC: Alexander Graf <agraf@suse.de> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/pci/pci-sysfs.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index aa012fb3834b..312f23a8429c 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);