Commit 400a6da1 authored by Michal Wajdeczko's avatar Michal Wajdeczko Committed by Lucas De Marchi
Browse files

drm/xe/configfs: Enforce canonical device names 



While we expect config directory names to match PCI device name,
currently we are only scanning provided names for domain, bus,
device and function numbers, without checking their format.
This would pass slightly broken entries like:

  /sys/kernel/config/xe/
  ├── 0000:00:02.0000000000000
  │   └── ...
  ├── 0000:00:02.0x
  │   └── ...
  ├──  0: 0: 2. 0
  │   └── ...
  └── 0:0:2.0
      └── ...

To avoid such mistakes, check if the name provided exactly matches
the canonical PCI device address format, which we recreated from
the parsed BDF data. Also simplify scanf format as it can't really
catch all formatting errors.

Signed-off-by: default avatarMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: default avatarLucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20250722141059.30707-3-michal.wajdeczko@intel.com
Signed-off-by: default avatarLucas De Marchi <lucas.demarchi@intel.com>
parent 0bdd05c2

drivers/gpu/drm/xe/xe_configfs.c

+8 −1
Original line number Diff line number Diff line
@@ -259,12 +259,19 @@ static struct config_group *xe_config_make_device_group(struct config_group *gro 
	unsigned int domain, bus, slot, function;

	struct xe_config_device *dev;

	struct pci_dev *pdev;

	char canonical[16];

	int ret;



	ret = sscanf(name, "%04x:%02x:%02x.%x", &domain, &bus, &slot, &function);

	ret = sscanf(name, "%x:%x:%x.%x", &domain, &bus, &slot, &function);

	if (ret != 4)

		return ERR_PTR(-EINVAL);



	ret = scnprintf(canonical, sizeof(canonical), "%04x:%02x:%02x.%d", domain, bus,

			PCI_SLOT(PCI_DEVFN(slot, function)),

			PCI_FUNC(PCI_DEVFN(slot, function)));

	if (ret != 12 || strcmp(name, canonical))

		return ERR_PTR(-EINVAL);



	pdev = pci_get_domain_bus_and_slot(domain, bus, PCI_DEVFN(slot, function));

	if (!pdev)

		return ERR_PTR(-ENODEV);