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authorChristoph Hellwig <hch@lst.de>2018-05-18 18:56:24 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-08-06 16:24:33 +0200
commit549f4ee6884758a683ab1e0245987a8a7a38563a (patch)
treedf9095057051dafdd5bc8a6d9fd73b8a863850f0 /drivers
parent40e082b99a1eb935dab65a869593617407483016 (diff)
PCI: Prevent sysfs disable of device while driver is attached
[ Upstream commit 6f5cdfa802733dcb561bf664cc89d203f2fd958f ] 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> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/pci/pci-sysfs.c15
1 files changed, 9 insertions, 6 deletions
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index ec91cd17bf34..5fb4ed6ea322 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -180,13 +180,16 @@ static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
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;
}