Commit 4efe874a authored Feb 04, 2015 by Sasha Levin Committed by Bjorn Helgaas Feb 24, 2015

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: 782a985d ("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>

parent c517d838

drivers/pci/pci-sysfs.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -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);

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