From adbeae33ffe1dfd86c5726a515cde90fff74e6e2 Mon Sep 17 00:00:00 2001 From: Michal Wajdeczko Date: Tue, 22 Jul 2025 16:10:55 +0200 Subject: [PATCH] drm/xe/configfs: Enforce canonical device names MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit [ Upstream commit 400a6da1e967c4f117e4757412df06dcfaea0e6a ] 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: Michal Wajdeczko Cc: Lucas De Marchi Reviewed-by: Lucas De Marchi Link: https://lore.kernel.org/r/20250722141059.30707-3-michal.wajdeczko@intel.com Signed-off-by: Lucas De Marchi Signed-off-by: Sasha Levin --- drivers/gpu/drm/xe/xe_configfs.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/xe/xe_configfs.c b/drivers/gpu/drm/xe/xe_configfs.c index 58c1f397c68c9..797508cc6eb17 100644 --- a/drivers/gpu/drm/xe/xe_configfs.c +++ b/drivers/gpu/drm/xe/xe_configfs.c @@ -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); -- 2.47.3