PCI: Prevent sysfs disable of device while driver is attached
Manipulating the enable_cnt behind the back of the driver will wreak
complete havoc with the kernel state, so disallow it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: Keith Busch <keith.busch@intel.com>
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 366d93a..788a200 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -288,13 +288,16 @@
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- if (!val) {
- if (pci_is_enabled(pdev))
- pci_disable_device(pdev);
- else
- result = -EIO;
- } else
+ device_lock(dev);
+ if (dev->driver)
+ result = -EBUSY;
+ else if (val)
result = pci_enable_device(pdev);
+ else if (pci_is_enabled(pdev))
+ pci_disable_device(pdev);
+ else
+ result = -EIO;
+ device_unlock(dev);
return result < 0 ? result : count;
}