Messages in this thread Patch in this message | | | From | Luis Henriques <> | Subject | [PATCH 3.16.y-ckt 103/165] PCI: Don't read past the end of sysfs "driver_override" buffer | Date | Wed, 25 Mar 2015 14:01:16 +0000 |
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3.16.7-ckt9 -stable review patch. If anyone has any objections, please let me know.
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From: Sasha Levin <sasha.levin@oracle.com>
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 <sasha.levin@oracle.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> CC: Alexander Graf <agraf@suse.de> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/pci/pci-sysfs.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 6d04771e4903..045b63ae97d5 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -516,7 +516,8 @@ 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); @@ -544,7 +545,7 @@ 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);
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