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| author | Bandan Das <bsd@redhat.com> | 2014-04-01 21:32:59 -0400 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2014-04-29 17:36:44 -0600 |
| commit | 8895d3bcb8ba960b1b83f95d772b641352ea8e51 (patch) | |
| tree | fe6a3d11c5e029fc59cef437afede23a63d91d60 /drivers/pci/pci-driver.c | |
| parent | 7c82126a94e69bbbac586f0249e7ef11e681246c (diff) | |
| download | linux-8895d3bcb8ba960b1b83f95d772b641352ea8e51.tar.bz2 | |
PCI: Fail new_id for vendor/device values already built into driver
While using the sysfs new_id interface, the user can unintentionally feed
incorrect values if the driver static table has a matching entry. This is
possible since only the device and vendor fields are mandatory and the rest
are optional. As a result, store_new_id() will fill in default values that
are then passed on to the driver and can have unintended consequences.
As an example, consider the ixgbe driver and the 82599EB network card:
echo "8086 10fb" > /sys/bus/pci/drivers/ixgbe/new_id
This will pass a pci_device_id with driver_data = 0 to ixgbe_probe(), which
uses that zero to index a table of card operations. The zeroth entry of
the table does *not* correspond to the 82599 operations.
This change returns an error if the user attempts to add a dynid for a
vendor/device combination for which a static entry already exists.
However, if the user intentionally wants a different set of values, she
must provide all the 7 fields and that will be accepted.
[bhelgaas: drop KVM text since the problem isn't KVM-specific]
Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/pci/pci-driver.c')
| -rw-r--r-- | drivers/pci/pci-driver.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index d911e0c1f359..650ce8935fd7 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -107,7 +107,7 @@ store_new_id(struct device_driver *driver, const char *buf, size_t count) subdevice=PCI_ANY_ID, class=0, class_mask=0; unsigned long driver_data=0; int fields=0; - int retval; + int retval = 0; fields = sscanf(buf, "%x %x %x %x %x %x %lx", &vendor, &device, &subvendor, &subdevice, @@ -115,6 +115,26 @@ store_new_id(struct device_driver *driver, const char *buf, size_t count) if (fields < 2) return -EINVAL; + if (fields != 7) { + struct pci_dev *pdev = kzalloc(sizeof(*pdev), GFP_KERNEL); + if (!pdev) + return -ENOMEM; + + pdev->vendor = vendor; + pdev->device = device; + pdev->subsystem_vendor = subvendor; + pdev->subsystem_device = subdevice; + pdev->class = class; + + if (pci_match_id(pdrv->id_table, pdev)) + retval = -EEXIST; + + kfree(pdev); + + if (retval) + return retval; + } + /* Only accept driver_data values that match an existing id_table entry */ if (ids) { |