From 10a4206a24013be4d558d476010cbf2eb4c9fa64 Mon Sep 17 00:00:00 2001 From: Danilo Krummrich Date: Tue, 24 Mar 2026 01:59:09 +0100 Subject: PCI: use generic driver_override infrastructure When a driver is probed through __driver_attach(), the bus' match() callback is called without the device lock held, thus accessing the driver_override field without a lock, which can cause a UAF. Fix this by using the driver-core driver_override infrastructure taking care of proper locking internally. Note that calling match() from __driver_attach() without the device lock held is intentional. [1] Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1] Reported-by: Gui-Dong Han Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789 Fixes: 782a985d7af2 ("PCI: Introduce new device binding path using pci_dev.driver_override") Acked-by: Bjorn Helgaas Acked-by: Alex Williamson Tested-by: Gui-Dong Han Reviewed-by: Gui-Dong Han Link: https://patch.msgid.link/20260324005919.2408620-6-dakr@kernel.org Signed-off-by: Danilo Krummrich --- drivers/xen/xen-pciback/pci_stub.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/xen') diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c index e4b27aecbf05..79a2b5dfd694 100644 --- a/drivers/xen/xen-pciback/pci_stub.c +++ b/drivers/xen/xen-pciback/pci_stub.c @@ -598,6 +598,8 @@ static int pcistub_seize(struct pci_dev *dev, return err; } +static struct pci_driver xen_pcibk_pci_driver; + /* Called when 'bind'. This means we must _NOT_ call pci_reset_function or * other functions that take the sysfs lock. */ static int pcistub_probe(struct pci_dev *dev, const struct pci_device_id *id) @@ -609,8 +611,8 @@ static int pcistub_probe(struct pci_dev *dev, const struct pci_device_id *id) match = pcistub_match(dev); - if ((dev->driver_override && - !strcmp(dev->driver_override, PCISTUB_DRIVER_NAME)) || + if (device_match_driver_override(&dev->dev, + &xen_pcibk_pci_driver.driver) > 0 || match) { if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL -- cgit v1.2.3