x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.

Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.

Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.

Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL.

Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")
Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com

1 files changed, 77 insertions, 0 deletions

diff --git a/drivers/usb/usbip/Kconfig b/drivers/usb/usbip/Kconfig
new file mode 100644
index 000000000..50945b6fa
--- /dev/null
+++ b/drivers/usb/usbip/Kconfig
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: GPL-2.0
+
+config USBIP_CORE
+	tristate "USB/IP support"
+	depends on NET
+	select USB_COMMON
+	select SGL_ALLOC
+	help
+	  This enables pushing USB packets over IP to allow remote
+	  machines direct access to USB devices. It provides the
+	  USB/IP core that is required by both drivers.
+
+	  For more details, and to get the userspace utility
+	  programs, please see <http://usbip.sourceforge.net/>.
+
+	  To compile this as a module, choose M here: the module will
+	  be called usbip-core.
+
+	  If unsure, say N.
+
+config USBIP_VHCI_HCD
+	tristate "VHCI hcd"
+	depends on USBIP_CORE && USB
+	help
+	  This enables the USB/IP virtual host controller driver,
+	  which is run on the remote machine.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called vhci-hcd.
+
+config USBIP_VHCI_HC_PORTS
+	int "Number of ports per USB/IP virtual host controller"
+	range 1 15
+	default 8
+	depends on USBIP_VHCI_HCD
+	help
+	  To increase number of ports available for USB/IP virtual
+	  host controller driver, this defines number of ports per
+	  USB/IP virtual host controller.
+
+config USBIP_VHCI_NR_HCS
+	int "Number of USB/IP virtual host controllers"
+	range 1 32
+	default 1
+	depends on USBIP_VHCI_HCD
+	help
+	  To increase number of ports available for USB/IP virtual
+	  host controller driver, this defines number of USB/IP
+	  virtual host controllers as if adding physical host
+	  controllers.
+
+config USBIP_HOST
+	tristate "Host driver"
+	depends on USBIP_CORE && USB
+	help
+	  This enables the USB/IP host driver, which is run on the
+	  machine that is sharing the USB devices.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called usbip-host.
+
+config USBIP_VUDC
+	tristate "VUDC driver"
+	depends on USBIP_CORE && USB_GADGET
+	help
+	  This enables the USB/IP virtual USB device controller
+	  driver, which is run on the host machine, allowing the
+	  machine itself to act as a device.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called usbip-vudc.
+
+config USBIP_DEBUG
+	bool "Debug messages for USB/IP"
+	depends on USBIP_CORE
+	help
+	  This enables the debug messages from the USB/IP drivers.